• Journal of Food Hygiene and Safety
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• v.36 no.3
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• pp.228-238
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• 2021

The aim of this research was to develop a rapid and easy multi-residue method for determining dimethipin, omethoate, dimethipin, chlorfenvinphos and azinphos-methyl in agricultural products (hulled rice, potato, soybean, mandarin and green pepper). Samples were prepared using QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and analyzed using gas chromatography-tandem mass spectrometry (GC-MS/MS). Residual pesticides were extracted with 1% acetic acid in acetonitrile followed by addition of anhydrous magnesium sulfate (MgSO₄) and anhydrous sodium acetate. The extracts were cleaned up using MgSO₄, primary secondary amine (PSA) and octadecyl (C₁₈). The linearity of the calibration curves, which waas excellent by matrix-matched standards, ranged from 0.005 mg/kg to 0.3 mg/kg and yielded the coefficients of determination (R²) ≥ 0.9934 for all analytes. Average recoveries spiked at three levels (0.01, 0.1, 0.5 mg/kg) and were in the range of 74.2-119.3%, while standard deviation values were less than 14.6%, which is below the Codex guideline (CODEX CAC/GL 40).

• Journal of Food Hygiene and Safety
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• v.36 no.3
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• pp.220-227
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• 2021

Fluoroimide is a fungicide and is also used as a pesticide for persimmons and potatoes. The established fluoroimide pesticide analysis method takes a long time to perform and uses benzene, a carcinogen. In addition, a lower limit of quantification is required due to enforcement of the Positive List System. Therefore, this study aimed to improve the analysis method for residual fluoroimide to resolve the problems associated with the current method. The analytical method was improved with reference to the increased stability of fluoroimide under acidic conditions. Fluoroimide was extracted under acidic conditions by hydrogen chloride (4 N) and acetic acid. MgSO₄ and NaCl were used with acetonitrile. C₁₈ (octadecylsilane) 500 mg and graphitized carbon black 40 mg were used in the purification process. The experiment was conducted with agricultural products (hulled rice, potato, soybean, mandarin, green pepper), and liquid chromatograph-tandem mass spectrometry was used for the instrumental analysis. Recovery of fluoroimide was 85.7-106.9% with relative standard deviations (RSDs) of less than 15.6%. This study reports an improved method for the analysis of fluoroimide that might contribute to safety by substituting the use of benzene, a harmful solvent. Furthermore, the use of QuEChERS increased the efficiency of the improved method. Finally, this research confirmed the precise limit of quantification and these results could be used to improve the analysis of other residual pesticides in agricultural products.

• Journal of Food Hygiene and Safety
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• v.36 no.3
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• pp.271-279
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• 2021

Sweet pumpkin is rich in minerals such as calcium, phosphorus and fiber, and also contains a large amount of β-carotene, which has antioxidant effects. In this study, Makgeolli containing steaming sweet pumpkin (SP) was manufactured to enhance the antioxidant activity. To prepare the Makgeolli, SP was added in amounts of 5, 10, 20, and 30% (w/w), and the chemical (pH, total acidity, alcohol), microbiological (lactic acid bacteria, yeast) properties, and antioxidant activities (DPPH, ABTS) were examined during fermentation and storage for 9 days. The pH of SP Makgeolli was 4.00-4.23 at day 1 of fermentation, and then the pH gradually decreased as fermentation progressed, showing the lowest results at day 9 (3.28-3.52). At day 1, the total acidity was significantly increased (P<0.05) as the amount of SP (0-30%; 0.09-0.55%) and the total acidity in SP Makgeolli (1.01-1.20) was also rapidly increased by 5 days of fermentation. Alcohol content was significantly increased (P<0.05) as the amount of SP (0-30%; 4.59-5.77%) increased at day 9. The counts of lactic acid bacteria and yeast in SP Makgeolli were 8.0-8.1 and 7.9-7.8.0 CFU/mL, respectively, which was higher than SP 0% at day 9. DPPH and ABTS radical scavenging activities were significantly increased (P<0.05) as the amount of SP (0-30%; 48.29-78.97% for DPPH, 62.12-86.68% for ABTS) increased at day 9. This study suggests that Makgeolli added with SP could be potentially and commercially developed due to its superior microbiological and chemical properties, including high antioxidant activities.

• Journal of Food Hygiene and Safety
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• v.36 no.3
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• pp.248-256
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• 2021

A total of 120 samples corresponding to 12 categories of dried processed fishery products distributed in Gyeonggi-do were examined for radioactivity contamination (¹³¹I, ¹³⁴Cs, ¹³⁷Cs) and heavy metals (lead, cadmium, arsenic, and mercury). One natural radioactive material, ⁴⁰K, was detected in all products, while the artificial radioactive materials ¹³¹I, ¹³⁴Cs and ¹³⁷Cs were not detected at above MDA (minimum detectable activity) values. The detection ranges of heavy metals converted by biological basis were found as follows: Pb (N.D.-0.332 mg/kg), Cd (N.D.-2.941 mg/kg), As (0.371-15.007 mg/kg), Hg (0.0005-0.0621 mg/kg). Heavy metals were detected within standard levels when there was an acceptable standard, but the arsenic content was high in most products, although none of the products had a permitted level of arsenic. In the case of dried processed fishery products, there are products that are consumed by restoring moisture to its original state, but there are also many products that are consumed directly in the dry state, so it will be necessary to set permitted levels for heavy metals considering this situation in the future. In addition, Japan has decided to release contaminated water from the Fukushima nuclear power plant into the ocean, so there is high public concern about radioactivity contamination of food, including fishery products. Therefore, continuous monitoring of various food items will be necessary to ease consumers' anxiety.

• Journal of Life Science
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• v.31 no.5
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• pp.475-480
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• 2021

Interest in edible insects such as Protaetia brevitarsis has increased rapidly, and several insect producers use these insects in industrialized mass production. However, mass rearing of insects can cause insect diseases. Sprouted barley is a valuable source of nutrients and has antioxidant, antimicrobial, anti-inflammatory, and anti-cancer effects. This study was conducted to investigate the effect of sprouted barley as a feed additive for producing healthy P. brevitarsis larvae. P. brevitarsis larvae were fed feeds with or without sprouted barley, and their body weight and larval period wewe checked weekly. To confirm the antibacterial effects of sprouted barley, in vitro bioassays were performed by counting Serratia marcescens colonies, and in vivo bioassays were performed by determining the survival rate and body weights of the S. marcescens-infected larvae. Larvae fed different feeds were analyzed for their nutrient compositions (i.e., such as proximate composition, minerals, amino acids, and heavy metals). Larvae fed 5% and 10% sprouted barley had maximum weight increases of 19.2% and 23.1%, respectively. Both treatment groups had significantly shorter larval periods than those of the control group. Sprouted barley markedly inhibited the growth of entomopathogenic S. marcescens. Furthermore, larvae fed sprouted barley exhibited higher Cu, Zn, and K levels. Seventeen amino acids were present in larvae fed sprouted barley, of which, tyrosine and glutamic acid were predominant. No heavy metals were detected in any of the investigated groups. Therefore, sprouted barley may be a suitable feed additive for producing high-quality P. brevitarsis larvae.

• Journal of The Korean Association For Science Education
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• v.41 no.2
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• pp.93-102
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• 2021

In this study, we investigated the characteristics of inquiry problems set by high school students who observed an 'unexpected phenomenon' and identified the effects of providing scientific information on setting inquiry problems. The subjects of this study were 126 eleventh grade students in Seoul that were randomly assigned to group A (N=66) and group B (N=60). In the study, watching a video of about 45 seconds of the unexpected phenomenon repeatedly for 20 minutes, all the students freely wrote inquiry problems that they wanted to carry out in their handouts. At this time, it is characterized that only the handout of group B additionally included scientific information on the unexpected phenomenon. As a result of the study, students, regardless of group, set more 'curiosity-oriented inquiry problems (i.e., focusing on inquiries they want to do rather than revealing what might be the cause of the phenomenon)' rather than going into a 'cause-oriented inquiry problem solving (i.e., revealing the cause of the phenomenon).' Among the curiosity-oriented inquiry problems, most of them were 'new-result inquiry problems (i.e., investigating what new results will occur by simply manipulating experimental situations).' It was also found that students who were provided with the scientific information tended to set significantly more inquiry problems using the provided information than those who were not (χ2(1)=8.996, p<.01), nevertheless the students with the scientific information did not set significantly more cause-oriented inquiry problems (χ2(1)=1.376, p>.05). The findings have been discussed from the four perspectives (i.e., lack of provided information, lack of opportunities to internalize the provided information, personal curiosity-seeking, and intuitive thinking), and implications for inquiry problem setting were suggested.

• Journal of Korean Elementary Science Education
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• v.40 no.2
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• pp.239-252
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• 2021

The purpose of this study is to develop an evolutionary STEAM education program based on the brain and to analyze its effects on scientific interest and scientific creativity of elementary school students. Four different topics based on four scientific fields (Physics, Chemistry, Biology and Earth Science) were derived from the science textbook under the 2015 revised curriculum to build a brain-based evolutionary STEAM education program. The research subjects were 90 fourth graders of S-elementary school located in Gyeonggi Province, Korea and they were divided into an experimental group of 45 students and a comparative group of 45 students. The main findings of this study are as follows. First, according to the independent samples t-test of scientific interest, no statistically significant difference were found between the two groups, but the brain-based evolutionary STEAM education had meaningful effect on improving 'interest in scientific learning' and 'anxiety about scientific learning'. Second, according to the paired samples t-test of scientific interest, the experimental group had significantly improved 'interest in science' but on the other hand, there was no effect on the comparative group. Third, scientific creativity and originality of the experimental group were significantly higher after the class than that of the comparative group. Fourth, although there were some significant differences between the two groups in scientific creativity after the class, both groups had improved scientific creativity between the results of pre and post test. Based on these results, we discuss implications for science education and STEAM education research.

• Journal of Food Hygiene and Safety
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• v.36 no.3
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• pp.239-247
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• 2021

In order to confirm the impact of the Positive List System (PLS) being applied to all agricultural products from January 1, 2019, we analyzed 28,693 points of inspection-related data on agricultural products distributed in Gyeonggi-do from 2018 to 2020. The ratio of cases exceeding the standard for the total inspection performance was 1.0% in 2018, 1.2% in 2019, and 1.2% in 2020. Out of the 114 cases exceeding the standard in 2019, 55 were applied on a Maximum Residue Limit (MRL) of 0.01 mg/kg, and out of the 115 cases exceeding the standard in 2020, 66 were applied on a MRL of 0.01 mg/kg. To improve this, it seems necessary to manage unintentional pollution, conventional use for unregistered crops, and illegal pesticides. Fluquinconazole detection resulted from unintentional contamination, and diazinon, chlorothalonil, and methabenzthiazuron detection resulted from conventional use in unregistered crops. Chinomethionat is a pesticide component that was discarded in the past and its current use has been attributed to the smuggling of pesticides. This study and future monitoring data can be used as reference data for system supplementation and on-site management reinforcement.

• Journal of Internet of Things and Convergence
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• v.7 no.2
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• pp.55-63
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• 2021

The purpose of this study was to investigate the structural relationship between the use motives of the Internet of Things (IoT), which was presented as a technology strategy priority for university students, on usage attitudes, usability performance and life satisfaction. From April 1 to April 30, 2021, a non-face-to-face survey was conducted targeting university students living in Gwangju Metropolitan City and Jeollanam-do, and the study was conducted in a total of 213 copies. The collected questionnaires were analyzed using IBM's SPSS 21.0 and AMOS 21.0 programs. The research results are as follows. First, the motivation for using IoT was found to have an effect on usage attitude, and it was found to have an effect on life satisfaction and also on usage performance. Second, it was found that the attitude of using the Internet of Things had an effect on the usability performance. However, it was found that there was no effect on life satisfaction. Third, it was found that the use of IoT has an effect on the life satisfaction of college students. Fourth, it was found that the indirect effect on the attitude of use had an indirect effect on the relationship between the motivation for use and the performance of use. However, it was found that there was no indirect effect on the relationship between use motivation and life satisfaction. Fifth, the indirect effect on the usability performance was found to have an indirect effect on the relationship between use motivation and life satisfaction, Also, it was found that there was an indirect effect on the relationship between usage attitude and life satisfaction. Sixth, in the relationship between use motivation and life satisfaction, there was no double indirect effect via use attitude and utilization performance. Based on these results, the motivation for using the Internet of Things for college students and a solution to the information gap were proposed.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.2
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• pp.19-34
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• 2021

The government budget for promoting startup have been skyrocketed as catching up with increasing demands for high-tech startup by disruptive innovation resulted from rapid technology change. However, major trend of startup have still fallen on self-employed type of startup due to the lack of expertise and fund in spite of desperate government policy efforts. In reality, the access to high-tech startup has been very limited and too high huddle to would-be entrepreneur. This paper implement empirical analysis on the effects of entrepreneur competency and satisfaction level to government support, considering these as the KSF for the growth and success of high-tech startup, to the performance of the company. In particular, it focus on defining unique characteristics of high-tech startup through differential proving by the backgrounds of entrepreneur such as major, R&D experience, patent possession, CTO possession. This research carry out survey to 217 entrepreneurs in high-tech company in Daejon and Daegue at R&D Special Innopolis Zone. Research results are as follow. First, entrepreneurial achievement competencies, conceptualization competencies, network competencies and market recognition competencies positively affect the financial and non-financial performance and organizational and technical competencies, while organizational and technological competencies only positively impact on non-financial performance. Second, the satisfaction level of government support showed a positive moderating effect on entrepreneurial achievement competencies and financial performance, while no significant effect in other competencies. Third, positive differential effect by the technological background of entrepreneur such as Major, R&D experience, patent possession, CTO possession) have been confirmed. This paper deliver several significant implications and contributions, First, it propose classified and systematized entrepreneur competency through the domestic and foreign literature reviews. Second, it proves the need for the wider spread of team based startup culture rather then sole startup. Third, it also proves the important role of technological background of entrepreneur among the characteristics of high-tech startup.