• Korean Journal of Agricultural Science
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• v.50 no.2
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• pp.241-247
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• 2023

Erwinia amylovora , which causes fire blight disease on apple and pear trees, is one of the most important phytopathogens because of its devastating impact. Currently, the only way to effectively control fire blight disease is through the use of antibiotics such as streptomycin, kasugamycin, or oxytetracycline. However, problems with the occurrence of resistant strains due to the overuse of antibiotics are constantly being raised. It is therefore necessary to develop novel disease control methods through an advanced understanding of the pathogenesis mechanism of E. amylovora . To better understand the pathogenesis of E. amylovora , we investigated unknown virulence factors by random mutagenesis and screening. Random mutants were generated by Tn5 transposon insertion, and the pathogenicity of the mutants was assessed by inoculation of the mutants on apple fruitlets. A total of 17 avirulent mutants were found through screening of 960 random mutants. Among them, 14 mutants were already reported as non-pathogenic strains, while three mutants, TS3128_M2899 (ΔSUFU ), TS3128_M2939 (ΔwcaG ), and TS3128_M3747 (ΔrecB ), were not reported. Further study of the association between E. amylovora pathogenicity and these 3 novel genes may provide new insight into the development of control methods for fire blight disease.

• Physical Therapy Korea
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• v.31 no.1
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• pp.63-71
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• 2024

Background: Individuals with pes planus tend to overuse the extrinsic foot muscles, such as the tibialis anterior (TA) and peroneus longus (PL), to compensate for the weakened intrinsic foot muscles, such as the abductor hallucis (AbdH). Furthermore, differences in weight-bearing can affect the activity of muscles in both the intrinsic and extrinsic foot muscles. To date, no study has compared the effects of the short foot exercise (SFE) and toe spread-out exercise (TSO) on intrinsic and extrinsic foot muscle activity and the corresponding ratios in different weight-bearing positions. Objects: To compare the effects of the SFE and TSO on AbdH, TA, and PL activity and the AbdH/TA and AbdH/PL activity ratios in the sitting and standing positions in individuals with pes planus. Methods: Twenty participants with pes planus were recruited. Surface electromyography was used to assess the amplitudes of AbdH, TA, and PL activity. Participants performed both exercises while adopting both the sitting and standing positions. Results: No significant interaction between exercise and position was found regarding the activity of any muscle or ratio of the activity, except for PL activity. We observed a significant increase in AbdH activity during the TSO compared to the SFE, and no significant difference in TA and PL activity between the two exercises. AbdH, TA, and PL activity were significantly higher in the standing position than in the sitting position. Furthermore, the AbdH/PL activity ratio significantly increased in the sitting position, although there was a significant increase in AbdH activity in the standing position. Conclusion: In individuals with pes planus, we recommend performing the TSO in the sitting position, which may increase the activity of the AbdH while concurrently decreasing the activity of the TA and PL, thus strengthening the AbdH.

• Journal of Drive and Control
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• v.21 no.2
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• pp.53-64
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• 2024

Global population growth has resulted in an increased demand for food production. Simultaneously, aging rural communities have led to a decrease in the workforce, thereby increasing the demand for automation in agriculture. Drones are particularly useful for unmanned pest control fields. However, the current method of uniform spraying leads to environmental damage due to overuse of pesticides and drift by wind. To address this issue, it is necessary to enhance spraying performance through precise performance evaluation. Therefore, as a foundational study aimed at optimizing drone-based pest control technologies, this research evaluated water-sensitive paper (WSP) via density map estimation using convolutional neural networks (CNN) with a encoder-decoder structure. To achieve more accurate estimation, this study implemented multi-task learning, incorporating an additional classifier for image segmentation alongside the density map estimation classifier. The proposed model in this study resulted in a R-squared (R²) of 0.976 for coverage area in the evaluation data set, demonstrating satisfactory performance in evaluating WSP at various density levels. Further research is needed to improve the accuracy of spray result estimations and develop a real-time assessment technology in the field.

• Journal of Industrial Convergence
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• v.22 no.3
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• pp.111-120
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• 2024

This study aimed to examine the effect of the depression on fatigue among university students by mediating smartphone overuse, which would be expected to help to lead healthy school life. Participants were composed of the 193 university students and performed a self-report questionnaire including depression, fatigue, smartphone overdependence, and demographic characteristics. Data was analyzed using SPSS 25.0 along with the PROCESS macro program. The main findings were as follows. Depression had a significant effect on fatigue among university students (F=8.180, p<.001), and smartphone overdependence was significantly mediated between depression and fatigue (B=.120, p<.001). These findings suggest that psychological aspects should be considered when developing intervention programs aimed at reducing fatigue levels of university students. Furthermore, the efforts to appropriate use of smartphones are needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.309-316
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• 2020

The aim of this study was to identify the relationship between smartphone usage time and oral health among Korean adolescents using data from the 13th (2017) Korea Youth Health Behavior Survey, which included 62,276 subjects. The daily smartphone usage time was categorized as not used, less than 2 hours, more than 2 hours, less than 4 hours, and more than 4 hours. Our results reveal that 60.1% of participants and 61.7% of smartphone users experienced oral disease symptoms annually, 27.4% of total adolescents used smartphone more than 4 hours daily during weekdays, and 53.8% more than 4 hours daily on weekends. The results from multivariate logistic regression analysis adjusting general characteristics show that the adjusted odds ratio (aOR) for risk of oral disease experience was 1.78 (95% confidence interval, CI 1.67-1.91) times higher in the group that used smartphones more than 4 hours a day on weekdays and 1.81 (95% CI 1.70-1.93) times higher in the group that used smartphones more than 4 hours a day on weekends compared to the group that did not use smartphones. The results indicate that smartphone overuse among Korean adolescents has a harmful effect on oral health. Education programs for reducing excessive use of smartphones among adolescents will help promote oral health.

• Journal of the Korea Society of Computer and Information
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• v.25 no.3
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• pp.163-168
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• 2020

In this paper we propose a The purpose of this study was to examine the psychological characteristics of youth mobile phone use. Internally, we want to find out about self-regulation, interpersonal relationship, pleasure, and desire to achieve reality. For the research, the Korea Information Society Agency utilized 568 data based on self-control and user motivation among long-term tracking data of Internet and mobile phone addiction in 2018. The SPSS window 23 version was used for data analysis, and the data collected were analyses to identify the subject's demographic characteristics. In addition, the correlation of variables between groups was investigated by analyzing dummy variables, and the results of the study were as follows. First, the addiction was slightly higher in mobile phone game groups than in social network service (SNS) groups, but in the same period of use, social network service (SNS) groups showed a higher desire for interpersonal relationships. In the desire to avoid reality, mobile phone game groups showed a higher gap than social network service (SNS) However, there was no difference between groups in terms of pleasure and desire to achieve. The results of this study indicated that the content of mobile phone use differed in factors affecting mobile phone overuse, and suggestions for follow-up research were discussed.

• Korean Journal of Biological Psychiatry
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• v.6 no.2
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• pp.176-188
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• 1999

Objective : The purpose of this study was to evaluate the effects of alcohol on neurocognitive function, psychomotor performance and subjective response in healthy Korean adults with different ALDH2 genotypes. Method : A total of 24 males, half with active $ALDH2^*1/2^*1$ and the other with inactive $ALDH2^*1/2^*2$, was selected through genotyping using restriction fragment length polymorphism. In a double-blind, placebo-controlled cross-over design, each subject consumed 0.5g/kg dose of alcohol, given as a mixture of 40% vodka and orange juice, and placebo(orange juice) on two separate occasions on an average of weekly intervals. The blood alcohol concentrations(BACs) were measured using a breath analyzer at baseline and at 30, 60 minutes after drinking. P300s were measured at baseline and at 30 minutes after alcohol and placebo intake. Vital signs and psychomotor performance[Critical Flicker Fusion Threshold(CFFT), Choice Reaction Time (CRT), Digit Symbol Substitution(DSS)] were measured at baseline and at 60 minutes after alcohol and placebo intake. Subjective responses were measured at the end of the study. The statistical analysis focused on whether there were any differences between groups with different ALDH2 genotypes. Results : The major results are as follows. 1) BACs in the inactive group were overall equivalent to those in the active group. Only in terms of time, BACs were significantly higher overall at 30 minutes than at 60 minutes after alcohol intake. 2) Pulse rates were significantly increased after alcohol intake compared with placebo, and the increase was greater in the inactive than in the active group. 3) P300 latencies in leads Fz(frontal), Cz(cental) and Pz(parietal) were significantly increased after alcohol intake compared to placebo, and the increase was greater in the inactive than in the active group. P300 amplitudes in leads Cz and Pz were significantly decreased overall after alcohol intake compared to placebo. 4) Compared with placebo, alcohol produced significant effect on the psychomotor performance : impairment in the inactive group, improvement in the active group. 5) Compared with placebo, alcohol significantly induced a negative or an intense effect on the subjective responses in the inactive group, but little negative and even a somewhat positive effect in the active group. Conclusions : These results suggest that ALDH isozyme variance might be an important factor to determine the effects of acute dose of alcohol on the various psychobehavioural functions and also to determine the alcohol use pattern and to predict the future development of alcohol overuse and/or abuse.

• The Korean Journal of Mycology
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• v.11 no.2
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• pp.79-84
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• 1983

To study physiological and ecological characters of the secondary mycelia of Armillariella mellea, it was cultivated on the various media. It was grown very well on the malt extract medium compared with its growth on yeast extract medium, potato dextrose medium and Hamada medium. The temperature of $27^{\circ}C$ gave the best condition for it to grow. The highest rate of growth was shown in medium of pH 6. Heteroauxin of 5 ppm concentration showed a increase as 26.2% in growth in compared with the control group. Gibberelline 10ppm, Tomatoton of 10,000 dilution and Adoton of 5,000 dilution showed positive effect. It was shown that the use of above hormones in appropriate concentration brought the effect of growth, but overuse of them brought inhibitory effect. Under the same condition of 200ppm concentration, vitamin A gave the highest growth of 18.2% than that of the control used.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.6
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• pp.79-89
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• 2014

The purpose of this study is to draw the implication for building domestic housing-related co-operatives by understanding activities of housing-related co-operatives from case study and by suggesting the start-up typology for possible domestic housing-related co-operatives and requisites for building them. According to their activities housing-related co-operatives are categorized into three types which are housing supply and operation type, maintain and improve the existing housing type, and design and performance improvement type. National housing policy should be connected to housing co-operatives indirectly. That is, the policy direction ought to be not toward controlling housing co-operatives, letting them supply more houses directly, but toward supporting voluntary co-operatives, showing them the overall housing policy blueprint. Co-operatives cannot be a panacea. Too much protection or support for co-operatives could lead to a reverse discrimination against private companies, and the co-operatives might overuse this kind of prominent position. We need to focus on the possibility of the role of co-operatives as a facilitator for local economy rather than a perfect substitute for the existing economy system.

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.329-341
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• 2014

This study investigated the differences of internet addiction by gender and the psychological states(depression, anxiety, impulislvity and aggression) by internet addiction groups and the relationship of depression, anxiety, impulsivity and aggression with internet addiction by resilience as moderator. The 529 college students (male: 212, female: 317) of 5 universities of Jeonbuk Province participated in this study. Main results are as follows; First, the intenet addiction level of male college students was higher than female students, and the higher internet addiction was, the higher depression and impulsivity were. Second, depression. anxiety, impulsivity and resilience were correlated with internet addiction. But aggression was not correlated with it. Third, anxiety and implusivity(male college students), depression and impulsivity(female college students) were correlated with internet addiction or overuse. Fourth, resilience was proved to function as moderator in the prediction of depression on internet addiction of only female college students. The limitation and future tasks were discussed.