• Horticultural Science & Technology
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• v.33 no.3
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• pp.429-434
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• 2015

Apple blotch-like symptoms (ABLS) were observed on 'Fuji' apple leaves in Cheongsong, Gunwi and Yeongcheon apple orchards located in Gyeongbuk Province during 2010-2014. Characteristics of ABLS were yellowing, brown spots on leaves, and defoliation, similar to apple blotch diseased (ABD) leaves, which are infected with Marssonina coronaria. It is difficult to differentiate by eye between ABLS and ABD, which has led to misdiagnosis and overuse of fungicides. The present study was conducted to investigate the cause of ABLS using stereomicroscopy, culture isolation, cross-sectional analysis of leaves, and PCR. No acervuli were found on the surface of ABLS leaves and no growth was observed on potato dextrose agar (PDA) plates in culture. Furthermore, cross-sectional analysis revealed similar results, and mycelia were absent in ABLS leaves. By contrast, all these characteristics were present in ABD leaves. Furthermore, no fungi or viruses were detected in ABLS leaves by PCR, suggesting that the disease is not caused by these agents. These findings suggest that ABLS might be a physiological disorder in plants that is distinct from ABD.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.223-233
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• 2002

The air distribution duct with multiple outlets is an essential part of automotive air-conditioning system In a bus. The estimation of airflow rate in an automotive air-conditioning duct is typically very complicate due to large variations in cross-sectional area and abrupt changes in flow direction, as well as unbalanced distribution of the flow. In this paper, the flow characteristic in a duct with multiple outlets is investigated through experiment, CFD simulation and a one-dimensional simulation. Numerical simulations have been performed for two simplified air conditioning ducts with multiple outlets used in a medium bus. The three dimensional Navier-Stokes code was used to evaluate the overall pressure, velocity Held, and distribution rate at each diffuser according to the change of various design parameters such as ratio of cross-sectional area and radius of bifurcated region. In addition, a one-dimensional program based on Bernoulli equation was developed to obtain optimized diffuser area required to equalize discharge flow rate at each outlet. As a result of this study, optimized diffuser area of design variable by one-dimensional program was very reasonable as compared to the trend deduced from CFD Simulation. Therefore, the simple and convenient one-dimensional analysis developed in this study can be applied in practical design procedure for air-conditioning duct.

• The Journal of Korean Medicine
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• v.39 no.2
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• pp.80-91
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• 2018

Objectives: The purpose of this study was to investigate stress and health recognition in Korean medical student by gender. Methods: 393 Korean medical student participated in this study. They were surveyed demographic characteristics(gender, age, drinking, morning diet, health recognition and etc), medical stress scale, Maslachh burnout inventory, Korea acceptance and action, and Ego Resilience Scale. For statistical analysis, chi-square test, Student t-test, correlation analysis, and simple regression analysis has been used. Results: In Medical stress scale and ego resilience, it is not significant difference by gender. Female students were significantly higher than male students in Maslach burnout inventory(P=0.015). Male students were significantly higher than female students in Korea Acceptance and Action(P=0.002). Health recognition have negative correlation between medical stress and academic exhaustion, and positive correlation between psychological flexibility and ego resilience. Conclusions: Through these results, we need to further study and develop strategies to reduce stress according to gender in Korean medical college.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.1
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• pp.69-75
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• 2016

Polydimethylsiloxane (PDMS) is used as a scaffold for cell culture. Because both the stress and strain acting on the substrate and the hemodynamic environment are important for studying mechano-transduction of cellular function, the traction force of the surface of a substrate has been measured using fluorescence images of particle distribution. In this study, deformation of the cross-sectional plane of a PDMS block was measured by correlating particle image distributions to validate the particle image strain measurement technique. Deformation was induced by a cone indentor and a shearing parallel plate. Measured deformations from particle image distributions were in agreement with the results of a computational structure analysis using the finite-element method. This study demonstrates that the particle image correlation method facilitates measurement of deformation of a polymer scaffold in the cross-sectional plane.

• Health Policy and Management
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• v.19 no.4
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• pp.33-52
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• 2009

Health promotion policies have needed to assess in detailed and evidence-based work to set a policy goal and clear future directions of health promotion in Korea. To identify the major factors related with health promotion, we assessed the associations between public health outcome (potential years of life loss, PYLL) and national health determinants. For this purpose, we used a pooled cross sectional time-series regression analysis with corrected fixed effect models involving sixteen member countries of the Organisation for Economic Cooperation and Development during the period 1970 to 2001. The PYLL was positively associated with tobacco and alcohol consumption (model 1 and 2) and calories intake (model 2 and 3) while the PYLL was negatively associated with GDP, fruit and vegetable intake (model 2), number of doctors (model 3), coverage rates of health care security, and elderly population rates (model 4). In conclusion, health behaviors related with tobacco, alcohol, and nutrition were significant health determinants for health outcome. Overall analysis results of this study will provide a guidance toward improved macro- and micro-policy development for future health promotion policy in Korea.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.75-84
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• 2019

This study was a cross-sectional descriptive research that investigate the level of addiction and analyzed the impact of computer game addiction from 20 to 30 years old on communication capabilities. The purpose of this study was to investigate the level of game addiction according to general characteristics and to confirm the effect of computer game addiction on communication ability. There were a total of 220 participants in the study. This survey for this study was a self-reporting questionnaire, research tools for this study were developed by Lee (2000) using game addiction and Communication ability developed by Frits et al., (1999). Data analysis was analyzed with frequency analysis, t-test, ANOVA, and Regression using SPSS 18.0. As a result of analysis, the difference between game addiction and communication ability by gender was appeared to be different under statistical significance levels: game addiction (t=-.9.2, p<0.01), subcomponents of communication ability, concentration (t=7.20, p<0.01), understanding (t=6.13, p<0.01), response (t=6.22, p<0.01), memory (t=2.88, p<0.05). The highest level of game addiction was appeared between 28 and 30 years old under statistical significance (p<0.01). Finally computer game addiction affects understanding, a subcomponent of communication capabilities.

• Child Health Nursing Research
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• v.30 no.2
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• pp.77-86
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• 2024

Purpose: This study examined the combined effects of sugar-sweetened beverage (SSB) consumption, screen-based sedentary behaviors, and sleep duration on adolescent obesity. Methods: It followed a cross-sectional study design and conducted secondary analysis on data from 20,497 high school students who participated in the 17th (2021) Korea Youth Risk Behavior Web-based Survey. This study underwent logistic regression analysis in complex sampling analysis. Results: The combinations of low and medium consumption of SSBs, excessive screen-based sedentary behaviors, and short sleep durations were associated with a 1.18 and 1.12 fold increased likelihood of obesity (95% confidence interval [CI]=1.03-1.35) and (95% CI=1.02-1.22), respectively. The combination of high SSB consumption, appropriate screen-based sedentary behaviors, and short sleep duration (adjusted odds ratio [aOR]=1.15, 95% CI=1.01-1.31) and high SSB consumption, excessive screen-based sedentary behaviors, and short sleep duration (aOR=1.40, 95% CI=1.16-1.69) were associated with obesity. Conclusion: Integrated and tailored programs considering combination patterns of SSB consumption, screen-based sedentary behaviors, and short sleep duration need to be developed for preventing adolescent obesity.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.108-111
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• 2004

Structural dynamic characteristics and aeroelastic stability of a small-scale bearingless rotor system have been investigated. A flexbeam is one of the most important component of bearingless hub system. It must have sufficient torsional flexibility as well as baseline stiffness in order to produce feathering motion. In the present paper, a cross-shaped composite flexbeam has been proposed for a guarantee of torsional flexibility and flapwise and lagwise bending stiffness. One dimensional elastic beam model was used for the construction of a structural model. Equivalent isotropic sectional stiffness was used in the blade model, and the flexbeam was regarded as anisotropic; which has ten independent stiffness quantities. CAMRAD II has been used for the analysis of structural dynamic characteristics of the bearingless rotor system. Rotational natural frequencies and aeroelastic stability at hovering have been investigated. Analysis result shows that the cross-shaped flexbeam has the rotational natural frequency tuning capacity.

• Transactions of Materials Processing
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• v.18 no.4
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• pp.323-328
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• 2009

The prediction of drawing load is very important in the drawing process. However, it is not easy to calculate the drawing load for the shape drawing process through a theoretical model because of a complex arbitrary final cross section shape. The purpose of this study is to predict drawing load in shape drawing process. The cross section of product is divided with small angle as much as similar with fan-shape. The drawing load of each section was calculated by theoretical model of round to round drawing process. And the shape drawing load was determined by summation of drawing load of each section. The effectiveness of the proposed method was verified through the FE analysis and shape drawing experiment. It had a good agreement between proposed method, FE analysis and experiment within about 3% errors.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.175-182
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• 2001

Effective length factor approach for framed column design has long played an important design-aid role. This approach, however, is effective only when the columns are in the form of prismatic or uniform cross sections. Structural engineers who have to design or analyse framed columns with variable cross sections need some means to do their job. By using the finite element method, the stability analysis of the isolated compression members with variable cross sections and that of the framed columns are performed. The parameters considered in the stability analysis are taper and sectional property parameters of the columns, the second moment of inertia ratio of beam to column, and beam span to column height ratio. On the basis of the stability analysis results, effective length factor formulas for the columns with variable sections are derived.