• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.4
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• pp.1-10
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• 2023

As a result of climate change, non-point source pollution (NPS) from farmland with the steep slope during the rainy season is expected to have a significant impact on the water system. This study aimed to evaluate the effect of furrow mulching using alfalfa and PAM (Polyacrylamide) materials for each rainfall event, while considering the load characteristics of NPS. The study was conducted in Wanju-gun, Jeollabuk-do, in 2022, with a testbed that had a slope of 13%, sandy loam soil, and maize crops. The testbed was composed of four plots: bare soil (Bare), No mulching (Cont.), Vegetation mulching (VM), and PAM mulching (PM). Runoff was collected from each rainfall event using a 1/40 sampler and the NPS load was calculated by measuring the concentrations of SS, T-N, T-P, and TOC. During farming season, the reduction efficiency of NPS load was 37.1~59.5% for VM and 38.2~75.7% for PM. The analysis found that VM had a linear regression correlation (R²=0.28~0.86, P-value=0.01~0.1) with elapsed time of application, while PM had a quadratic regression correlation (R²=0.35~0.80, P-value=0.1). These results suggest that the selection of furrow mulch materials and the appropriate application method play a crucial role in reducing non-point pollution in farmland. Therefore, further studies on the time-series reduction effect based on the application method are recommended to develop more effective preemptive reduction technologies.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.579-586
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• 2004

The objective of the present prospective trial was to compare the efficacy of chlorhexidine(Cervitec), Fluoride (Fluorprotector) and combination of chlorhexdine and fluoride varnishes in decreasing the level of salivary mutans streptococci. Forty healthy students of school of dentistry, Chonbuk national university were investigated to evaluate mutans streptococci(MS) counts and randomized into four groups to treat with the experimental varnishes; A) untreated group(n=10), B) chlorhexidine group(n=10), C) fluoride group(n=10), D) chlorhexidine and fluoride group(n=10). Dentocult $SM^{(R)}$ (Orion Diagnostica) strip method was used for measurement of the level of mutans streptococci in saliva. Stimulated saliva were collected at baseline for mutans streptococci counts evaluation (ms1), 12 weeks later the completion of each varnish treatment, mutans streptococci counts were re-evaluated. In varnish group with chlorhexidine, fluoride and combination of chlorhexidine and fluoride, the level of mutans streptococci was lower after 12 weeks than at baseline, but there were no significant differences in saliva(p>0.05), when compared with baseline. After 12 weeks, a remarkable reduction was still found in the subjects with high level of mutans streptococci at baseline, but not different in the low and moderate level of mutans streptococci(p>0.05).

• Journal of Biomedical Engineering Research
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• v.37 no.6
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• pp.215-221
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• 2016

Conformity between the femoral component and tibial insert within the knee replacement may be measured in frontal or sagittal view, and shows differences in the curvature radius of the femoral component depending on the flexion angle, i.e., curvature radius has a complex effect on contact stress. Therefore, it is essential to confirm how the curvature radius effects contact stress, and provide an important variable to reduce contact stress. This study correlated contact stress with curvature radius measured in frontal and the sagittal views and confirmed the effect of curvature radius for assessment of the Newly Designed Unicompartment Knee Replacement (NDUKR). Finite element models were constructed for NDUKR and $Zimmer^{(R)}$ Unicompartment High Flex Knee Replacement system (ZUKR), incorporating the curvature radius as measured in either frontal or sagittal view. The femoral component had 1200N of compressive load applied approximately 1.65xbody weight. Contact stress was predicted at flexion angles $0^{\circ}C$, $30^{\circ}C$, $60^{\circ}C$, $90^{\circ}C$ and $120^{\circ}C$, for NDUKR: 42, 47.7, 47.7, 51.2, and 54.1 MPa, and ZUKR: 41.2, 49.5, 53.2, 54.3, and 57.4 MPa, respectively. Correlation analysis showed the influence of curvature radius measured from the sagittal view was larger than for frontal view.

• Journal of Korean Academy of Nursing
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• v.37 no.4
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• pp.549-557
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• 2007

Purpose: The purpose of this study was to identify the relationship among job stress, family stress and perceived health status of middle school teachers and to present basic information about promoting health and coping with stress. Method: Participants(N=547) was recruited in B city from November 2005 to December 2005. Data were analyzed with descriptive statistics, t-test, ANOVA, Pearson's correlation and multiple regression. Results: The degree of Job stress of the middle school teachers was 54.47 out of a total score of 88; that of family stress was 46.57 out of a total score of 96; and that of perceived health status was 78.59 out of the perfect score 100. There was a significantly negative relationship between job stress and perceived health status (r=-.274, p<.001), and family stress and perceived health status(r=-.408, p<.001). However, there was a positive relationship between job stress and family stress(r=.298, p<.001).Family stress, gender, charging subject, job stress, charging grade and number of family member was 27.1% of the variance in perceived health status of middle school teachers. Conclusion: Family stress has the most important impact on perceived health status with middle school teachers. Based on the finding, we could conclude that both job stress and family stress management should be required to improve perceived health status.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.135-136
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• 2016

SUPER concrete poontoon is developed to overcome shortcomings about corrosion problem of steel pontoon and the insufficient freeboard line of concrete pontoon. Top slab of Pontoon resists truck load or sidewalk live load. The soffit slab and outer wall of Pontoon resist the horizontal and vertical components of wave pressure, and those were loaded along X and Y-axis of Pontoon. Global analysis for the Pontoon is carried out to design its cross-sections economically using a geometric non-linear time history analysis method by Strand7 and buoyance-stability calculated automatically on non-vertical boundary conditions. And the load-capacity of Pontoon is confirmed through mock-up tests.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.709-717
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• 2012

To establish the standard of ripe kiwifruit sorting, near infrared (NIR) spectroscopy was performed on kiwifruit sampled from three farms. Destructive measurements of flesh firmness, soluble solids content (SSC), and acidity were performed and compared to measurement using NIR reflectance spectrums from 408 to 2,492 nm. NIR predictions of those quality factors were calculated using the modified partial least square regression method. Flesh firmness was predicted with a standard error of prediction (SEP) of 3.32 N and with a correlation coefficient ($R^2$) of 0.88. SSC was predicted with SEP of $0.49^{\circ}Brix$ and with $R^2$ of 0.98. Acidity was predicted with SEP of 0.28% and with $R^2$ of 0.91. Kiwifruit ripened at $20^{\circ}C$ for 15 days showed uneven qualities with normal distribution. Considering the SEP of each parameter, kiwifruit after ripening treatment could be non-destructively predicted their qualities and sorted by flesh firmness or soluble solids content through NIR prediction.

• Korean Journal of Food Science and Technology
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• v.18 no.2
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• pp.88-92
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• 1986

Determination of bacterial adenosine triphosphate (ATP) based on luciferin-luciferase bioluminescene reaction was applied to the measurement of bacteria on the surface of chicken as an alternative rapid method. The light yield was proportional to the concentration of ATP giving a straight line within a range of $10^{-10}\;to\;10^{-6}M$. The bacteria isolated from the surface of chicken were identified as Escherichia coli, Hafnia alvei, Pseudomonas putida and Aeromonas hydrophila. When the ATP contents of each bacteria were determined by bioluminescence reaction and compared, there was no significant difference (r = 0.95). The Patterns of growth curves for E. coli look very similar, when the bacterial growth was monitored by ATP content and viable cell count. When bacterial ATP of each samples collected every 2 days during storage for 14 days at $4^{\circ}C$was determined and compared with viable cell count, it gave a good correlation (r = 0.95, n = 32).

• Korean Journal of Veterinary Service
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• v.32 no.3
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• pp.265-273
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• 2009

A cross-sectional survey was undertaken to identify risk factors and clinical signs associated with parasitic helminth infections of cattle in Mymensignh district of Bangladesh. A nonrandom convenience sampling method was used to select 138 animals from 40 farmers/herds. The eggs per gram of faeces (epg) for nematodes and trematodes were determined by McMaster and Stoll's methods respectively. Animal-level and herd-level data were recorded by means of a questionnaire. Multi-collinearity amongst explanatory variables were assessed using $2{\times}2{\times}\;X^2$ test and one variable in a pair was dropped if $P{\leq}0.05$ formultiple logistic regression models. Association study between outcome and explanatory variables was conducted using classification tree, random forests and multiple logistic regression. A positive epg was considered as infected. Analyses were performed using $STATA^{(R)}$, version 8.0/Intercooled and $R^{(R)}$, Version 2.3.0. Seventy eight percent of the cattle were found to be infected with at least one type of helminth. Twenty four pairs of combinations of explanatory variables showed significant associations. Male animals (OR=3.3, P=.006, 95% CI=1.4, 7.7) were associated with significantly increased prevalence of nematode infection. Female cattle of the study area are mostly cross-breed, kept indoor, fed relatively good diet and not used for draught purpose. Males are used for draught purpose thereby more exposed to nematode infective stage and provided with relatively poor diet. So stressed male cattle may become more susceptible to nematode infection. All of the three statistical techniques selected gender and lumen motility as most important variables in association with nematode infection in cattle. The result of this survey can only be extrapolated to the periurban cattle population of traditional management system.

• Nuclear Engineering and Technology
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• v.38 no.2
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• pp.147-154
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• 2006

Thermal fatigue of the coolant circuits of PWR plants is a major issue for nuclear safety. The problem is especially accute in mixing zones, like T-junctions, where large differences in water temperature between the two inlets and high levels of turbulence can lead to large temperature fluctuations at the wall. Until recently, studies on the matter had been tackled at EDF using steady methods: the fluid flow was solved with a CFD code using an averaged turbulence model, which led to the knowledge of the mean temperature and temperature variance at each point of the wall. But, being based on averaged quantities, this method could not reproduce the unsteady and 3D effects of the problem, like phase lag in temperature oscillations between two points, which can generate important stresses. Benefiting from advances in computer power and turbulence modelling, a new methodology is now applied, that allows to take these effects into account. The CFD tool Code_Saturne, developped at EDF, is used to solve the fluid flow using an unsteady L.E.S. approach. It is coupled with the thermal code Syrthes, which propagates the temperature fluctuations into the wall thickness. The instantaneous temperature field inside the wall can then be extracted and used for structure mechanics computations (mainly with EDF thermomechanics tool Code_Aster). The purpose of this paper is to present the application of this methodology to the simulation of a straight T-junction mock-up, similar to the Residual Heat Remover (RHR) junction found in N4 type PWR nuclear plants, and designed to study thermal striping and cracks propagation. The results are generally in good agreement with the measurements; yet, in certain areas of the flow, progress is still needed in L.E.S. modelling and in the treatment of instantaneous heat transfer at the wall.

• Korean Journal of Adult Nursing
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• v.17 no.3
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• pp.379-388
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• 2005

Purpose: This study was conducted to explore the degree of depression, perceived health status, chronic disease and quality of life(QOL) among rural elderly and to determine the factors related to their QOL. Method: The design of this study was a correlational study. The subjects were 423 elderly consisted of 157(37.1%) men and 266(62.9%) women dwelling in a rural area of N City. Data were collected from May to December, 2003 using a structured questionnaire. A stepwise multiple regression analysis was performed to identify the factors related to the QOL. Result: It was found that the mean score of QOL was in total with 2.15 out of 5.00 and women elderly's score was significantly lower than men(t=2.20, p=.028). Perceived health status showed statistically significant positive relationship with QOL(r=.608, p<.05), while depression(r=-.751, p<.01) and chronic illness(r=-.336, p<.01) showed statistically significant negative relationship. Depression was found to have the highest correlation with QOL among the subjects. Depression score explained QOL at the most, accounting for 36.8% of the variability, followed by perceived health(8.2%) and the number of chronic illness(.7%). Other factors related to the QOL were economic status and absence of spouse. Conclusion: In order to increase the QOL of rural elderly, it is necessary to decrease the depression, to increase their perceived health status and to decrease the number of chronic illness. We suggest the implementation of a program not only to promote physical health status and self-care ability but to take care of mental health for the rural elderly.