• Journal of the Korean earth science society
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• v.27 no.6
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• pp.643-652
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• 2006

Data of the carbon monoxide concentration observed in Mt. Waliguan in China (WLG), Ulaan Uul in Mongolia (UUM), Tae-ahn Peninsula in Korea (TAP), and Ryori in Japan (RYO) were analyzed for a long period between 1991 and 2004. The annual average concentration of carbon monoxide was the highest at TAP $(233{\pm}41ppb)$ followed by $RYO(171{\pm}36ppb),\;UUM(155{\pm}26ppb),\;and\;WLG(135{\pm}22ppb)$. The seasonal variations being high in spring and low in summer were observed in other areas of Eastern Asia except WLG. TAP was high in carbon monoxide concentration in all seasons compared to WLG, UUM and RYO and shows wide distribution of concentration in the histogram, which is caused by the influence of large-scale air pollution due to its downwind location close to the East Asian continent, China in particular. Also, our data was compared with data measured at Mauna Loa (MLO) in Hawaii. According to the origin of the isentropic backward trajectory and its transport passage, carbon monoxide concentration observed in TAP was analyzed as follows: continental background airflows (CBG) were $216{\pm}47ppb$; regionally polluted continental airflows (RPC) were $316{\pm}56ppb$; Oceanic background airflows (OBG) were $108{\pm}41ppb$; and Partly perturbed oceanic airflows (PPO) were $161{\pm}6ppb$. The high concentration of carbon monoxide in TAP is due to the airflow from East Asian continent origin rather than that from the North Pacific origin. Especially, RPC which passes through the eastern China appeared to be the highest in concentration in spring, fall, and winter. However, OBG was affected by the North Pacific air mass with a low carbon monoxide concentration in summer. The NOAA satellite images and GEOS-CHEM model simulation confirmed a large-scale air pollution event that was in the course of expansion from southeastern China bound to the Korean Peninsula and the Korea East Sea by way of the Yellow Sea.

• Journal of the Korean earth science society
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• v.24 no.5
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• pp.428-439
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• 2003

Landslides, as a geological hazard, have caused extensive damage to property and sometimes result in loss of life. Thus, it is necessary to assess vulnerable areas for future possible landslides in order to mitigate the damage they cause. For this purpose, spatial data integration has been developed and applied to landslide hazard mapping. Among various models, this paper investigates and discusses the effectiveness of the Bayesian spatial data integration approach to landslide hazard mapping. In this study, several data sets related to landslide occurrences in Jangheung, Korea were constructed using GIS and then digitally represented using the likelihood ratio function. By computing the likelihood ratio, we obtained quantitative relationships between input data and landslide occurrences. The likelihood ratio functions were combined using the Bayesian combination rule. In order for predicted results to provide meaningful interpretations with respect to future landslides, we carried out validation based on the spatial partitioning of the landslide distribution. As a result, the Bayesian approach based on a likelihood ratio function can effectively integrate various spatial data for landslide hazard mapping, and it is expected that some suggestions in this study will be helpful to further applications including integration and interpretation stages in order to obtain a decision-support layer.

• Journal of the Korean earth science society
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• v.32 no.4
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• pp.360-372
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• 2011

In order to clarify the advection and dispersion characteristics of volcanic tephra to be emitted from the Mt. Baekdu, several numerical experiments were carried out using three-dimensional atmospheric dynamic model, Weather and Research Forecast (WRF) and Laglangian particles dispersion model FLEXPART. Four different temporally averaged meteorological values including wind speed and direction were used, and their averaged intervals of meteorological values are 1 month, 10 days, and 3days, respectively. Real time simulation without temporal averaging is also established in this study. As averaging time of meteorological elements is longer, wind along the principle direction is stronger. On the other hands, the tangential direction wind tends to be clearer when the time become shorten. Similar tendency was shown in the distribution of volcanic tephra because the dispersion of particles floating in the atmosphere is strongly associated with wind pattern. Wind transporting the volcanic tephra is divided clearly into upper and lower region and almost ash arriving the Korean Peninsula is released under 2 km high above the ground. Since setting up the temporal averaging of meteorological values is one of the critical factors to determine the density of tephra in the air and their surface deposition, reasonable time for averaging meteorological values should be established before the numerical dispersion assessment of volcanic tephra.

• Journal of Environmental Science International
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• v.26 no.5
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• pp.573-584
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• 2017

In order to simulate a typhoon precisely, the satellite observation data has been assimilated using WRF (Weather Research and Forecasting model) three-Dimensional Variational (3DVAR) data assimilation system. The observation data used in 3DVAR was GPS Radio Occultation (GPS-RO) data which is loaded on Low-Earth Orbit (LEO) satellite. The refractivity of Earth is deduced by temperature, pressure, and water vapor. GPS-RO data can be obtained with this refractivity when the satellite passes the limb position with respect to its original orbit. In this paper, two typhoon cases were simulated to examine the characteristics of data assimilation. One had been occurred in the Western Pacific from 16 to 25 October, 2015, and the other had affected Korean Peninsula from 22 to 29 August, 2012. In the simulation results, the typhoon track between background (BGR) and assimilation (3DV) run were significantly different when the track appeared to be rapidly change. The surface wind speed showed large difference for the long forecasting time because the GPS-RO data contained much information in the upper level, and it took a time to impact on the surface wind. Along with the modified typhoon track, the differences in the horizontal distribution of accumulated rain rate was remarkable with the range of -600~500 mm. During 7 days, we estimated the characteristics between daily assimilated simulation (3DV) and initial time assimilation (3DV_7). Because 3DV_7 demonstrated the accurate track of typhoon and its meteorological variables, the differences in two experiments have found to be insignificant. Using observed rain rate data at 79 surface observatories, the statistical analysis has been carried on for the evaluation of quantitative improvement. Although all experiments showed underestimated rain amount because of low model resolution (27 km), the reduced Mean Bias and Root-Mean-Square Error were found to be 2.92 mm and 4.53 mm, respectively.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.1
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• pp.15-21
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• 2015

Recently, attempts of replacing some of natural aggregate with mix of low quality aggregate are carried out for stable supply of aggregate. However, low quality aggregate such as recycled aggregate produced during the disposal process of construction wastes and by-product aggregate produced by industrial activities has problem of failing to comply to KS Standards. Therefore, we have compared fundamental properties of concrete by using granite crushed aggregate, recycled aggregate, blast furnace and electric arc furnace slag aggregate for effective utilization of lacking aggregate resources. As the result, slump in case of mixed use of aggregate was increased 0~10% compared to single use. Therefore, it is judged to be economically advantageous as it can expect effects in unit quantity or reduction of SP agent. Compressive strength in case of mixed use of aggregate was increased 0~10% compared to single use as it filled internal crevice of concrete with continuous particle size distribution. Accordingly, if we utilize by satisfying standard particle scope through mix of aggregate with different cause of formation in proper ratio, it was possible to confirm utility of mixed aggregate with demonstration of effects of increases of fluidity and compressive strength of concrete.

• Child Health Nursing Research
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• v.6 no.2
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• pp.212-223
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• 2000

The purposes of this research were to add to the developing knowledge base about the burden and social support of grandmothers involved with caring grandchildren, and to examine whether a significant relationship exists between their burden and social support perceived by the grandmothers. A convenience sample of 102 grandmothers was recruited from five collective apartment areas at a small city in Korea. The criteria of selection of sample were that the grandmothers were raising their grandchildren under the age of 36 months for 3 months or longer at own or gandchildren's home. The instruments used were a 15-item multidemensional burden scale and a 8-item social support scale. Both scales were self report, five point Likert type scales. The higher the score, the higher the degree of burden and social support. Data was collected by two prepared research assistants visiting subjects' home from December 10, 1998 to March 20, 1999. The collected data were analysed using mean, t-test, one-way ANOVA, and Pearson's correlation coefficient computed by SPSS software. The results were as follows. 1. In the age distribution of grandmothers, the over half of subjects(58.8%) were under 60 years old. The majority(69.6%) of subjects were married at time of data collection. 79(77.5%) of the sample reported that their perceived health status was good or over. 2. The burden of the grandmothers was not scored high, and the item means on burden scale were ranged from 2.26 to 4.19 out of 5. 'Short of private time'(4.19) had the highest score, followed by 'fatigue'(3.92), 'short of rest'(3.75), and 'short of contact with friends and neighbors'(3.62). The lowest item was 'family doesn't help me'(2.26), and followed by 'family doesn't understand me'(2.33), 'angry with family' (2.43), and 'angry while caring for grandchild'(2.60). 3. There were significant relationships between the burden and present health status(p<.01), childcaring confidence(p<.01), and motive of caring(p<.01). 4. The score of social support, was ranging from 3.61 to 4.01 out of 5. 5. The relationship between burden and social support was found to be correlated negatively. The relationship was statistically significant(γ= - .2833, p<.001). In conclusion, it was found that the burden was not high and burden of grandmothers caring grandchildren was correlated negatively to social support. Therefore, these results provide a basis for developing a nursing intervention to reduce the burden of grandmothers.

• Korean journal of applied entomology
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• v.17 no.2 s.35
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• pp.89-98
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• 1978

A study on the root-knot nematodes (Meloidogyne spp.) affecting economic crops in Korea was undertaken to know the distribution of the nemic fauna. Total 66 samples were taken from soil and root of 24 host plants at different localities in 4 provinces. Four Meloidogyne species such as Meloidogyne hapla, Meloidogyne arenaria, Meloidogyne incognita and Meloidogyne javanica were identified and some morphological characteristics were described. One of these, Meloidogyne javanica was reported newly in Korea from Horticultural Experimental Station, Suweon, Gyeong Gi on potato, Geomsadong, Daegu on chinese cabbage, Sangeogdong, Daegu, Gyeong Bug on violet and Choeumri, Namhae, Gyeong Nam on pumpkin. In Jae Ju province, Meloidogyne incognita was only found except the other three species. The most common and widely distributed Meloidogyne species in Korea is Meloidogyne hapla by $50\%$ in total, next Meloidogyne incognita $33.3\%$ Meloidogyne arenaria $10.6\%$ Meloidogyne javanica $6.0\%$ in turn, The root-knot nematodes infected the most severely in Jae Ju province and Gyeong Nam, Gyeong Bug and Gyeong Gi province in turn. Twenty four plants were attacked by root-knot nematodes among them important economic crops are soybean, peanut, potato, tomato, cucumber, carrot, pumpkin, wateremelon, edible burdock, pepper, eggplant, cabbage, lettuce and tobacco in Korea.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.6
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• pp.660-668
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• 2007

We investigated 248 patients who were diagnosed as malignant tumor in the department of Oral and maxillofacial Surgery of Kyungpook National University from 1999 to 2006, and following results were obtained. 1. Among 248 patients who have malignant tumor, 164 were men and 84 were women, which made the ratio of male to female 1.95:1. 2. The average age of oral cancer patients was 58.3. 3. As of the primary origin site, lower alveolus and gingiva were the greatest with 70 cases(28.2%), followed by tongue(l6.9%), upper alveolus and gingiva(14.9%), palate(13.7%), mouth floor(9.7%), buccal mucosa(4.8%), retromolar trigone(4.4%), Mx. & Mn. bone(3.2%) and lip(2.8%). 4. As of histologic distribution, squamous cell carcinoma was the greatest with 170 cases(68.6%), followed by sarcoma with 17 cases(6.9%), adenoid cystic carcinoma with 17 cases(6.9%), malignant lymphoma with 15 cases(6.0%), mucoepidermoid carcinoma with 13 cases(5.2%), metastatic carcinoma with 6 cases(2.4%) and malignant melanoma with 4 cases(1.6%). 5. Period between recognition of the symptom and the first visit to hospital was less than 3 months for 58.9% of the patients, and more than 3 months for 41% of the patients. 6. Investigation of whether the patients drink or smoke revealed that the number of non-smoking and non-drinking patients was 63 among 170 patients(37.0%) that were able to investigate. The number of patients who smoke only was 29(17.1%) and both drinking and smoking patients were 78(45.9%). 7. In clinical stage order, Stage IV(61.7%) was found th be the largest, followed by stage I(17.2%), stage II(13%) and stage III(7.8%). 8. The 5-year survival rate of the entire oral cancer patients appeared to be 57.7%. The survival rate was higher in younger group and women had higher survival rate but there was no statistical significance to this. In the aspect of stage, the survival rate was Stage I, Stage II, Stage IV and Stage III in decreasing order. The order according to T classification was the same. In N classification, patients with N0 had the highest survival rate and the survival rate decreased in the order of N1 and N2. Survival rate was especially low in patients with N2.

• Journal of the Economic Geographical Society of Korea
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• v.11 no.1
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• pp.59-77
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• 2008

The purpose of this study is to investigate the impact of traffic-related air pollution on the urban population in the Metropolitan Seoul area. In particular, this study analyzes urban population exposure to traffic-related particulate materials(PM). For the purpose, this study examines the relationships between traffic flows and PM concentration levels during the last fifteen years. Traffic volumes have been decreased significantly in recent year in Seoul, however, PM levels have been declined less compare to traffic volumes. It may be related with the rapid growth in the population and vehicle numbers in Gyenggi, the outskirt of Seoul, where several New Towns have been developed in the middle of 1990's. The spatial pattern of commuting has changed, and thus and travel distances and traffic volumes have increased along the main roads connecting CBDs in Seoul and New Towns consisting of large residential apartment complexes. These changes in traffic flows and travel behaviors cause increasing exposure to traffic-related air pollution for urban population over the Metropolitan Seoul area. GIS techniques are applied to analyze the spatial patterns of traffic flows, population distributions, PM distributions, and passenger flows comprehensively. This study also analyzes real time base traffic flow data and passenger flow data obtained from T-card transaction database applying data mining techniques. This study also attempts to develop a space-time model for assessing journey-time exposure to traffic related air pollutants based on travel passenger frequency distribution function. The results of this study can be used for the implications for sustainable transport systems, public health and transportation policy by reducing urban air pollution and road traffics in the Metropolitan Seoul area.

• Journal of Korean Society of Forest Science
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• v.107 no.2
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• pp.184-192
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• 2018

In this study was implemented to develop tree stem weight prediction equation of Larix kaempferi in central region by selecting a standard site, taking into account of diameter and position of the local trees. Fifty five sample trees were selected in total. By utilizing actual data of the sample trees, 11 models were compared and analyzed in order to estimate four different kinds of weights which include fresh weight, ovendry outside bark weight, ovendry inside bark weight and merchantable weight. As to estimate its weight, the study has classified its model according to three parameters: DBH, DBH and height, and volume. The optimal model was chosen by comparing the performance of model using the fit index and standard error of estimate and residual distribution. As a result, the formula utilizing DBH (Variable 1) is $W=a+bD+cD^2$ (3) and its fit index was 90~92%. The formula for DBH and height (Variable 2) is $W=aD^bH^C$ (8) and its fit index was 97~98%. In summation, Variable 2 model showed higher fitness than Variable 1 model. Moreover, fit index of formula for total volume and merchantable volume (W=aV) showed high rate of 98~99%, as well as resulting 7.7-17.5 with SEE and 8.0-10.0 with CV(%) which lead to predominately high fitness in conclusion. This study is expected to provide information on weights for single trees and furthermore, to be used as a basic study for weight of stand unit and biomass estimation equations.