• Korean Journal of Agricultural Science
• /
• v.50 no.4
• /
• pp.883-902
• /
• 2023

Water is critical to the health and productivity of fruit trees. Efficient monitoring of water stress is essential for optimizing irrigation practices and ensuring sustainable fruit production. Short-range sensing can be reliable, rapid, inexpensive, and used for applications based on well-developed and validated algorithms. This paper reviews the recent advancement in fruit tree water stress detection via short-range sensing, which can be used for irrigation scheduling in orchards. Thermal imagery, near-infrared, and shortwave infrared methods are widely used for crop water stress detection. This review also presents research demonstrating the efficacy of short-range sensing in detecting water stress indicators in different fruit tree species. These indicators include changes in leaf temperature, stomatal conductance, chlorophyll content, and canopy reflectance. Short-range sensing enables precision irrigation strategies by utilizing real-time data to customize water applications for individual fruit trees or specific orchard areas. This approach leads to benefits, such as water conservation, optimized resource utilization, and improved fruit quality and yield. Short-range sensing shows great promise for potentially changing water stress monitoring in fruit trees. It could become a useful tool for effective fruit tree water stress management through continued research and development.

• Journal of Digital Convergence
• /
• v.17 no.2
• /
• pp.413-421
• /
• 2019

This study examined the mediating effect of optimism on the relationship of middle school students' stress and happiness at school. 264 middle school students in Seoul were surveyed. The data were analyzed using descriptive statistics, t-test, correlation and multiple regression analysis. The results showed that: (1) The question means of stress and optimism were in the 'average' and 'slightly high'. The question mean of happiness at school was in the 'not happy' and 'slightly happy'. Females experienced higher level of stress than males. Males showed higher levels of happiness at school and optimism than females. (2) The stress, happiness at school and optimism were correlated. (3) The effect of stress on happiness at school was fully mediated by optimism. This study demonstrated that enhancing optimism is an effective strategy for improving the happiness at school. Finally, the findings were discussed from the convergence perspective.

• Human Ecology Research
• /
• v.59 no.2
• /
• pp.233-243
• /
• 2021

This study examined the longitudinal effects of media usage by early school-age children and of maternal parenting stress on children's school adjustment. The study focused on the mediating effect of executive function difficulty. Longitudinal data to examine the hypothetical model were drawn from the eighth (2015) through tenth (2017) waves of the Panel Study of Korean Children (PSKC) collected by the Korea Institute of Child Care and Education (KICCE). A total of 581 children (293 boys and 288 girls) and their mothers were included. Confirmatory factor analysis, structural equation model, and bootstrapping analysis were applied using SPSS 25.0 and Amos 26.0. The results are as follows. First, no significant correlation was found between early school-age children's media usage and maternal parenting stress. Second, neither media usage by early school-age children nor maternal parenting stress were found to directly affect children's school adjustment. Third, media usage by early school-age children and maternal parenting stress were shown to indirectly affect children's school adjustment via executive function difficulties. In other words, higher levels of media usage by early school-age children and maternal parenting stress during the first grade lead to greater executive function difficulties after a year, which, in turn, lead to a lower level of school adjustment in the third grade. This study indicates the need to develop practical support for the psychological wellbeing of mothers while they are performing their role as a parent and for children in maintaining suitable levels of media usage during early childhood.

• Journal of Preventive Medicine and Public Health
• /
• v.34 no.2
• /
• pp.141-148
• /
• 2001

Objective : To investigate the sources, extent and related factors in South Korean doctors. Methods : The study subjects were 934 doctors in Taegu, Kyungpook Province, Korea(540 independent practitioners, 105 employed at hospitals and 289 residents in training). Information concerning job stress was obtained using a 9-item questionnaire. Information regarding related factors such as demographic characteristics(age, sex, marital status), perceptions on the socioeconomic status of doctors and working conditions(work time, on-call days per week) was also obtained by self-administered questionnaire during April and May, 2000. Results : Major sources of job stress included clnical responsibility/judgement factor, patient factor and work loading factor. The job stress score of residents was the highest among three groups. The score was lower in older doctors. The score was low among those who thought doctors' socioeconomic status was not good. The longer the work time, the higher the job stress score was. Multiple regression analysis was conducted to control for the mutual influence of independent variables. In regression analysis, the score of residents was higher than practitioners. Work time and socioeconomic status perception had negative effects on job stress score. Conclusion : The average job stress score of the doctors was high. Age, work type, working conditions and perceptions of socioeconomic status were found to besignificantly related to job stress score. Although the job stress of doctors is somewhat inevitable due to the nature of the doctor's job, control of work time, development of coping tools and other intervention methods are needed to reduce job stress of doctors. Further studies are required to understand the characteristics of iob stress and reduce the job stress of doctors.

• The Korean Journal of Elementary Counseling
• /
• v.10 no.1
• /
• pp.19-38
• /
• 2011

The purpose of this study was to develop a cognitive-behavioral academic stress coping training for reduction of elementary school children's academic stress and improvement the ability to handle academically stressful situation with effective way, to examine its effects. For this, we assigned students of Y elementary school in Gyeongnam Province to two groups at random. From a group of 12 each, one group became the experimental group and the other the control group. And the program was applied twice a week to the experimental group who had totally six 40 minutes sessions of the research own making. Moreover, students evaluated the effects of the program via questionnaire regarding to academic stress and strategy for it. From 120 students of Y elementary school in Gyeongnam province for 3weeks, the study gathered data through the questionnaire for academic stressful situation to know this which students of elementary school often experience. From this, the results are reflected in the program. Also cognitive behavioral group counselling program for teenagers in crisis and existing programs used to adjust academic stress was redeveloped as available form for students in elementary school to compose the cognitive-behavioral Academic stress coping training. In short, the results of the study is as follows. In the study, first, It was showed that cognitive-behavioral academic stress coping training decreased stress which can be caused in situation causing academic stress with a school record, lesson, study and task. Second, The cognitive-behavioral academic stress coping training showed the effect to improve coping strategy for academic stress. In detail, a passive-aversive coping strategy and a helpful coping strategy of coping strategy was enhanced meaningfully but the effect getting to an active coping strategy was limited.

• The Korean Journal of Health Service Management
• /
• v.14 no.2
• /
• pp.93-104
• /
• 2020

Objectives: The purpose of this study was to investigate the relationship between oral health awareness symptoms and academic stress in some high school girls and to find out existing improvement plans. Methods: This study conducted a self-reported survey on 303 high school girls from four high schools in Jeollabuk-do. Results: Higher academic performance, poor subjective oral health, awareness of dental caries, awareness of jaw joint disease, awareness of discomfort during chewing, and awareness of tooth pain significantly increased overall admission stress. The most influential factors were dental pain symptoms, followed by subjective oral health and dental caries symptoms. Conclusions: Effective measures to help high school girls cope with academic stress, a systematic school oral health policy, and practical health promotion activities are necessary to improve their oral health.

• BMB Reports
• /
• v.46 no.10
• /
• pp.501-506
• /
• 2013

Oligodendrocyte precursor cells (OPCs) are most susceptible to oxidative stress in the brain. However, the cause of differences in susceptibility to oxidative stress between OPCs and mature oligodendrocytes (mOLs) remains unclear. Recently, we identified in vivo that ${\alpha}B$-crystallin (aBC) is expressed in mOLs but not in OPCs. Therefore, we examined in the present study whether aBC expression could affect cell survival under oxidative stress induced by hydrogen peroxide using primary cultures of OPCs and mOLs from neonatal rat brains. Expression of aBC was greater in mOLs than in OPCs, and the survival rate of mOLs was significantly higher than that of OPCs under oxidative stress. Suppression of aBC by siRNA transfection resulted in a decrease in the survival rate of mOLs under oxidative stress. These data suggest that higher susceptibility of OPCs than mOLs to oxidative stress is due, at least in part, to low levels of aBC expression.

• The Journal of the Korea Contents Association
• /
• v.20 no.1
• /
• pp.701-710
• /
• 2020

The purpose of this study is to investigate the moderating effect of anger expression styles on the relationship between school stress and interpersonal problem in adolescent. A total 300 students of middle and high school located in Chungcheongbuk-do completed the questionnaires to assess school stress, anger expression styles, and interpersonal problem during September to October, 2015 and 261 data were used in this report. Using multiple and hierarchical regression analysis, the results indicated that school stress, anger-in and anger-out significantly contributed to interpersonal problem. The interaction effect of school stress and anger expression styles were not significant. But anger-out significantly moderated the impact of school stress on domineering/controlling of interpersonal problem. These findings suggest that the intervention for preventing and relieving interpersonal problem in adolescent should focus on reducing school stress and maladaptive anger expression. Limitations and futre directions were discussed.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.8
• /
• pp.145-151
• /
• 2017

Many adolescents in high schools are experiencing school maladjustment by academic stress under the reality of higher-education-oriented schooling. A review of studies of academic stress and school adjustment reveals that ego-optimism is predicted as one of the moderating variables to help adolescents lessen academic stress and increase their school adjustment. The main purpose of this study was to verify the moderating effects of ego-resilience on the relationship between academic stress and school adjustment of adolescents. For this, 496 high school students of tenth and eleventh grade were respectively collected through cluster sampling to be surveyed, and then correlation analysis and moderated regression analysis were conducted. The major findings were as follows. First, there was a negative relationship between academic stress and school adjustment and between academic stress and ego-resilience, but a positive relationship between school adjustment and ego-resilience. Second, the moderating effects of ego-resilience on the relationship between academic stress and school adjustment were not found, although optimism, one of ego-resilience's sub-factors, had a significant moderating effect on them, implying that adolescents' optimism should be enhanced to lessen academic stress and ensure they have a successful school life. The study concludes that optimism is a protective factor for school adjustment caused academic stress and thus schools need to make active efforts to enhance their students' optimism.

• Steel and Composite Structures
• /
• v.27 no.1
• /
• pp.89-94
• /
• 2018

Uniaxial ratcheting behavior of Z2CND18.12N austenitic stainless steel used nuclear power plant piping material was studied. The results indicated that ratcheting strain increased with increasing of stress amplitude under the same mean stress and different stress amplitude, ratcheting strain increased with increasing of mean stress under the same stress amplitude and different mean stress. Based on least square method, a suitable method to arrest ratcheting by loading the materials was proposed, namely determined method of zero ratcheting strain rate. Zero ratcheting strain rate occur under specified mean stress and stress amplitudes. Moreover, three dimensional ratcheting boundary surface graph was established with stress amplitude, mean stress and ratcheting strain rate. This represents a graphical surface zone to study the ratcheting strain rates for various mean stress and stress amplitude combinations. The graph showed the ratcheting behavior under various combinations of mean and amplitude stresses. The graph was also expressed with the help of experimental results of certain sets of mean and stress amplitude conditions. Further, experimentation cost and time can be saved.