• Korean Journal of Psychosomatic Medicine
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• v.8 no.1
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• pp.20-30
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• 2000

Objective : This study was designed to investigate the frequencies and the relation of stressful life events and health problems and evaluate the influence of stressful life events on the physical symptoms and anxiety in adolescents. Method : Newcomb's 39-item life-event questionnaire and Newcomb's 19-item health problems questionnaire were administered to 475 adolescents. The frequencies of stressful life events and health problems which had actually occurred to them during the previous 12 months were investigated. Items of stressful life events were classified in 8 dimensional scaling factors(Family/parents, Accident/Illness, Sexuality, Autonomy, Deviance, Relocation, Distress, Items not in scales) and items of health problems were classified in 5 health problems(General, Heart and Lung, Nervous system, Anxiety, Psychosomatic symptoms) and the correlation between them was analyzed. Result : 1) The average number of events occurring during the past year for the 475 adolescents is 3(7.7%). The most frequent item of stressful life events was 'Thought about suicide' and dimensional factors of "Distress" and "Autonomy" were the most frequent life events in multidimensional sacling analysis. There were more factors of "Family/Illness" and " Autonomy" in male, while there was more factor of "Distress" in female. There were more factors of "School violence" and "Deviance" in younger students, while there were more factors of "Sexuality" and "Autonomy" in older students. 2) The most frequent item of health problem was 'excessive fatigue' and "anxiety" was most frequent health problem in multidimensional scaling analysis. There were more health problems in female than those in male. The higher grades the students became, the more health problems they have reported. 3) There was significant relationship between 7 factors of stressful life events except one factor of "Relocation" and 5 health problems. Conclusions : These findings suggest that as adolescents grow older, they are engaging in more controllable behaviors related to autonomy and sexuality and at the same time are experiencing increased difficulty with distressful or discomforting events, and their stressful life events are significantly related to decreased health and psychological functiong.

• Journal of Veterinary Clinics
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• v.32 no.6
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• pp.499-503
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• 2015

The objective of this study was to investigate arterial and venous blood gas, electrolytes, biochemical, and hematological values in healthy Korean native calves (KNC). The healthy 62 KNC within 3 weeks-old were examined. The arterial blood was collected from caudal auricular artery and the venous blood from jugular vein. The blood samples were analyzed immediately using a portable blood gas analyzer. The pH, $pO_2$, $pCO_2$, $cHCO_3{^-}$, BE, $cSO_2$, $Na^+$, $Ca^{2+}$, $Cl^-$, anion gap potassium (AgapK), Hct, cHgb, glucose, lactate and creatinine were determined. The normal values for blood gas, electrolytes, biochemical, and hematological variables determined in this study agree with other published values for normal calves. The mean concentration of glucose and lactate within 3 weeks old of KNC is higher than those of adult cattle. The blood values according to weeks of age within 3 weeks-old of arterial and venous blood variables were not significantly different (P > 0.05). Glucose (r = 0.927) had the strongest correlations between arterial and venous values. The correlation between the values of the arterial and the venous blood was strong in creatinine (r = 0.925), lactate (r = 0.815), $Ca^{2+}$ (r = 0.806), Hct (r = 0.799), $Na^+$ (r = 0.790), cHgb (r = 0.786), base excess (r = 0.749), pH (r = 0.710), $HCO_3{^-}$ (r = 0.710), and $cTCO_2$ (0.663). Analysis of blood samples in a field condition, using hand-held analyzer is rapid and useful in bovine practice.

• Journal of Food Hygiene and Safety
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• v.30 no.3
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• pp.227-235
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• 2015

Food-Health indicators have been developed and utilized internationally in the 'Food' domain of environment and health indicators. In Korea, however, Food Safety Health Indicators which are in the introductory stage had been developed separately from Environmental Health Indicators. The aim of the current study is to suggest feasible applications of the domestic Food Safety Health Indicators as a case study. We introduced 3 possible applications which are as follows: 1) production of two types of Integrated Food Safety Health Index; 2) conduction of correlation analysis between the Integrated Food Safety Health Index and Food Safety Health Indicators; 3) conduction of regression analysis to evaluate the relationship between the Integrated Food Safety Health Index and socioeconomic status. As a result, we provided the calculated Integrated Food Safety Health Index I and Integrated Food Safety Health Index II, which represents the regional food safety level in relative and absolute terms, respectively. Integrated Food Safety Health Index I was significantly correlated with the outbreaks of food-borne diseases (caused by Campylobacter jejuni, Bacillus cereus, Salmonella spp. and unknown cause) and incidence of E.coli infections. Integrated Food Safety Health Index II significantly decreased as the proportion of foreigners and women increased, and increased as the population density increased. Utilization of such Integrated Food Safety Health Indicators may be helpful in understanding the overall domestic food safety level and identifying the indicators which must be considered with priorities to enhance the food safety levels regionally and domestically. Furthermore, analyzing the association between Integrated Food Safety Health Index and factors other than food safety could be useful in conducting risk management and identifying susceptible populations. Food Safety Health Indicators can be useful in other applications, and may serve as a supporting material in establishing or modifying policy plans to enhance food safety. Therefore, keen interests by researchers accompanied by further studies on food safety health indicators are needed.

• Journal of The Korean Ophthalmological Society
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• v.59 no.11
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• pp.1024-1029
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• 2018

Purpose: We examined aqueous humor levels of 25-hydroxyvitamin D (vitamin D) in patients with age-related macular degeneration to investigate possible relationships between aqueous humor vitamin D levels and clinical manifestations. Methods: Patients > 50 years of age, 52 eyes of 34 patients with age-related macular degeneration, and 23 eyes of 17 patients treated with cataract surgery without retinal disease, were examined for aqueous humor vitamin D levels and compared. The experimental group was divided into two groups according to the median value of aqueous humor vitamin D levels. We compared the clinical manifestations of macular degeneration in both groups and identified relationships between aqueous humor vitamin D levels and clinical features. Results: Vitamin D levels in the aqueous humor were significantly lower in the experimental group than in the control group (experimental, $10.03{\pm}10.1ng/mL$ vs. control group, $40.8{\pm}16.4ng/mL$; p < 0.001). Patients with high vitamin D levels in the macular degeneration group had a higher percentage of fibrovascular pigment epithelial detachments than those in the low grade group (high grade group, 65% vs. low grade group, 27%; p = 0.003). Multiple linear regression analysis showed a significant correlation between vitamin D levels and the total number of anti-vascular endothelial growth factor intravitreal injections within 6 months (standardize coefficient, ${\beta}=-0.336$). Conclusions: Patients with wet age-related macular degeneration had significantly lower vitamin D levels in the aqueous humor compared to control group subjects of similar ages. However, in patients with macular degeneration, low vitamin D levels were associated with a greater number of intravitreal injections, while higher levels of vitamin D may lead to more advanced forms of fibrovascular retinal pigment epithelium and related low vision. These relationships were not always constant, so further studies on the relationships between local vitamin D levels and ocular disorders are needed.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.1
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• pp.101-119
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• 2022

Existing algal bloom monitoring is based on field sampling, and there is a limit to understanding the spatial distribution of algal blooms, such as the occurrence and spread of algae, due to local investigations. In this study, algal bloom monitoring was performed using an unmanned aerial vehicle and multispectral sensor, and data on the distribution of algae were provided. For the algal bloom monitoring site, data were acquired from the Mulgeum·Mae-ri site located in the lower part of the Nakdong River, which is the areas with frequent algal bloom. The Chlorophyll-a(Chl-a) value of field-collected samples and the Chl-a estimation formula derived from the correlation between the spectral indices were comparatively analyzed. As a result, among the spectral indices, Maximum Chlorophyll Index (MCI) showed the highest statistical significance(R²=0.91, RMSE=8.1mg/m³). As a result of mapping the distribution of algae by applying MCI to the image of August 05, 2021 with the highest Chl-a concentration, the river area was 1.7km², the Warning area among the indicators of the algal bloom warning system was 1.03km²(60.56%) and the Algal Bloom area occupied 0.67km²(39.43%). In addition, as a result of calculating the number of occurrence days in the area corresponding to the "Warning" in the images during the study period (July 01, 2021~November 01, 2021), the Chl-a concentration above the "Warning" level was observed in the entire river section from 12 to 19 times. The algal bloom monitoring method proposed in this study can supplement the limitations of the existing algal bloom warning system and can be used to provide information on a point-by-point basis as well as information on a spatial range of the algal bloom warning area.

• Journal of The Korean Association For Science Education
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• v.34 no.8
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• pp.703-718
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• 2014

This study sought to investigate learning progressions for astronomical systems which synthesized the motion and structure of Earth, Earth-Moon system, solar system, and the universe. For this purpose we developed ordered multiple-choice items, applied them to elementary and middle school students, and provided validity evidence based on the consequence of assessment for interpretation of learning progressions. The study was conducted according to construct modeling approach. The results showed that the OMCs were appropriate for investigating learning progressions on astronomical systems, i.e., based on item fit analysis, students' responses to items were consistent with the measurement of Rasch model. Wright map analysis also represented that the assessment items were very effective in examining students' hypothetical pathways of development of understanding astronomical systems. At the lower anchor of the learning progression, while students perceived the change of location and direction of celestial bodies with only two-dimensional earth-based view, they failed to connect the locations of celestial bodies with Earth-Moon system model, and they could recognized simple patterns of planets in the solar system and milky way. At the intermediate levels, students interpreted celestial motion using the model of Earth rotation and revolution, Earth-Moon system, and solar system with space-based view, and they could also relate the elements of astronomical structures with the models. At the upper anchor, students showed the perspective change between space-based view and earth-based view, and applied it to celestial motion of astronomical systems, and they understood the correlation among sub-elements of astronomical systems and applied it to the system model.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.762-770
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• 2016

This study intended to investigate environmental factors including soil and vegetation in order to understand the environmental and ecological characteristics of the Korean endemic species, Syringa fauriei. Syringa fauriei is mainly distributed along the valley and riverside of the Gangwondo and its population is located at an elevation of 121~520m. Consequent to a vegetation survey within natural populations, a total of 320 taxa were identified from 20 quadrates in 4 natural populations. The Syringa fauriei population was classified into Securinega suffruticosa dominant population, Acer pseudosieboldianum dominant population, Amorpha fruticosa dominant population and Sorbaria sorbifolia var. stellipila dominant population. According to the physical and chemical soil analysis, Syringa fauriei habitats contained 1.98~2.81% of organic matter and 0.13~0.20 mg/kg of total nitrogen. The concentrations of cation exchange capacities $K^+$, $Ca^{2+}$, and $Mg^{2+}$ were $0.10{\sim}0.33cmol^+/kg$, $3.44{\sim}20.53cmol^+/kg$, and $0.34{\sim}0.95cmol^+/kg$, respectively. Positive ion substitution capacity was $8.08{\sim}13.68cmol^+/kg$. The pH was 6.28~7.74. The importance value of Deutzia glabrata, Fraxinus rhynchophylla, Alangium platanifolium var. trilobum, Syringa fauriei, Juglans mandshurica, and Salix koreensis in the Syringa fauriei population were 86.99%, 43.97%, 23.01%,18.52, 18.40%, and 11.56%, respectively. Correlation analysis between the vegetation of Syringa fauriei populations and its environmental factors using DCCA revealed that the altitude above sea level and $Mg^{2+}$ were the most influential factors, while dominant populations of Securinega suffruticosa and Acer pseudosieboldianum were spread across areas with high percentages of pH, CEC, and $Mg^{2+}$. Acer pseudosieboldianum population was dispersed in areas with higher $K^+$ compared to Securinega suffruticosa population. The dominant population of Amorpha fruticosa was found to live in places with high altitudes above sea level and with high rates of available phosphate, $K^+$, and rock-exposure.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.517-528
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• 2007

Domestic or international existing researches regarding rail damage factors are focused on laying, vehicle conditions, driving speed and driving habits and overlook characteristics of track structure (elasticity, maintenance etc). Also in ballast track, as there is no special lateral spring stiffness of track also called as ballast lateral resistance in concrete track, generally, existing study shows concrete track has 2 time shorter life cycle for rail replacement than ballast track due to abrasion. As a result of domestic concrete track design and operation performance review, concrete track elasticity is lower than track elasticity of ballast track resulting higher damage on rail and tracks. Generally, concrete track has advantage in track elasticity adjustment than ballast track and in case of Europe, in concrete track design, it is recommended to have same or higher performance range of vertical elastic stiffness of ballast track but domestically or internationally review on lateral spring stiffness of track is very minimal. Therefore, through analysis of service line track on site measurement and analysis on performance of maintenance, in this research, dynamic characteristic behaviors of commonly used ballast and concrete track are studied to infer elasticity of service line track and experimentally prove effects of track lateral spring stiffness that influence curved rail damage as well as correlation between track elasticity by track system and rail damage to propose importance of appropriate elastic stiffness level for concrete and ballast track.

• Journal of the Korean Society of Radiology
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• v.5 no.3
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• pp.111-120
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• 2011

A purpose of study is to develop optimization and radiation dose exposure reference level by measuring actual radiation dose in condition of quality control of mammography equipment for 39 clinics. The result were as follows. First, we measured T-test separating radiology from general clinic. According to the test, mAs was measured at average 78.58 mAs; radiology at 80.16 mAs and general clinic at 77.22 mAs. And, kerma rate was measured at average 7.71 mGy/mR; radiology at 8.94 mGy/mR and general clinic at 6.66 mGy/mR. HVL was measured at average 0.42 mmAl; radiology at 0.40 mmAl and general clinic at 0.43 mmAl. Average glandular dose was measured at average 1.14 mGy; radiology at 1.09 mGy and general clinic at 1.19 mGy. Second, we measured value of mAs, HVL, processing method and so on dividing two groups. And, we compared and analyzed average value measured using T-test. As a result, there was significance level in SID(P<0.05). There was significance level in mAs(P<0.05). Because processor was measured at 1.00 mGy and CR at 1.17 mGy according to the processing method of radiology. Third, according to the correlation analysis, radiology had significance level between average glandular dose and mAs and general clinic had significance level between average glandular dose and SID(P<0.05). Forth, as a result of regression analysis, mAs affected 22.7%t of average glandular dose and SID affected 21.7% of average glandular dose, which had significance level(P<0.05). And, mAs affected 29.0% of average glandular dose in radiology and SID affected 29.1% of average glandular dose in general clinic, which was most influential.

• Korean Journal of Environmental Biology
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• v.27 no.2
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• pp.183-190
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• 2009

Characterization of the analysis of forest vegetation, soil environmental conditions and water quality were performed from March 2003 to March 2007. The two basins were characterized by cultivated area (Kaesim reservoir) and mountain area (Jangchan reservoir), and divided into eleven small basins, where dynamics of pollutants, forest vegetation and soil environmental conditions were surveyed. The vegetation can be divided into 10 types by $Z\ddot{u}rich$-Montpellier school's method. Pearson coefficients between vegetation type and water quality were correlated with dissolved oxygen (DO) in the Quercus variabilis community at the 5% level and total phosphorus (TP) in the Larix leptolepis plantation at the 1% level. Especially total phosphorous and total nitrogen increased in small basins where the proportion of cultivated and residential area increased. The analysis of influences of pollutant discharge on water quality showed that pollutant charge was very low in forest land area ($Y_{T-P}$=-0.0017X+0.2215, r=0.16, $Y_{COD}$=- 0.0395X+8.5051 r=0.47). The soil types of western area were comparatively simple, but those of eastern area were complicated with regosols, red-yellow soils, lithosoles, etc. The pH, total solid (TS) and volatile substance (VS) of the forest and agricultural land soils collected in each site were 5.4~6.9, 75.8~80.2%, and 3.80%~5.80%, respectively. According to the analytical result of soil environmental conditions, heavy metal contents fell short to the mean value of natural conditions. Runoff amount (Y) and depth of topsoil (X) were negatively correlated, $Y_{ron}=-1.0088X_{top}+35.378$ (r=0.68). The correlation was much lower in up-stream but much higher in down-stream, because permeation into soil particle was larger on down-stream due to its more or less gentle slope. Pearson coefficients between soil pH and water pH were statistically significant at 1% level.