• Journal of Preventive Medicine and Public Health
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• v.21 no.2 s.24
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• pp.307-319
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• 1988

In order to determine the contents of lead, cadmium and zinc, the tissues of the crussian carp, Carassius carassius, collected from the middle streams of the Nakdong river were examined. During the dry season from 8 to 15, March, 1987, six loci were selected to sample the fish and river water; five of them were the midstreams of the Nakdong river i. e., the vicinities of the Andong dam, the Nakdong bridge, the Waegwan bridge, Gangjung and Gaepori, the other one was the Kumho river around the Paldal bridge(see Fig. 1). The microanalyses of lead and cadmium contents were undertaken by the atomic absorption spectrophotometer(Model IL-551) connected with CTF-IL 655, while that of Zinc by the flame method with IL551 only. The contents of lead and cadmium in water sampled from Gaepori distant from about 30km downward from the junction with the Kumho river were about 1.5 times higher than those from Gangjung distant about 0.5km upward from the junction, and the content of zinc from Gaepori was slightly higher than that from Gangjung. However, the contents of lead and cadmium in water sampled from Gaepori were three fifth of those from the vicinity of Paldal bridge far about 2km upperward from the junction. In the other words, the contents of lead and cadmium in the samples from the vicinity of the Paldal bridge were about 2.5 to 3 times higher than those from the Gangjung and 5 times higher than those from the Andong dam. The contents of the heavy metals in the tissues of Carassius carassius were relatively consistent to those of the aquatic environments where the fish were collected, with higher contents in the tissues of the crussian carp collected from the vicinity of Gaepori and the Paldal bridge which were so much polluted than in those from other loci in upper stream from the junction. And the contents of lead and cadmium in tissues were positively correlated with the age of the fish, however, that of zinc was not. The contents of lead in bone of crussian carp from the vicinity of the Paldal bridge in the group of 0-1 year old fish were similar to those of 4-5 years old fish from Gaepori, and higher than those of 3-4 years old fish collected from the upper stream of the junction. It is likely that fishing from Gaepori and the paldal bridge is not recommended, and all the industrial producers have to pay intensive attention to the water pollution due to the sewage disposal.

• The Journal of Engineering Geology
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• v.25 no.4
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• pp.533-545
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• 2015

Spatial and seasonal variations in hydrogeochemical characteristics and the factors affecting the deterioration in quality of shallow portable groundwater in an agricultural area are examined. The aquifer consists of (from the surface to depth) agricultural soil, weathered soil, weathered rock, and bedrock. The geochemical signatures of the shallow groundwater are mostly affected by the NO₃⁻ and Cl⁻ contaminants that show a gradual downward increase in concentration from the upper area, due to the irregular distribution of contamination sources. The concentrations of the major cations do not varied with the elapsed time and the NO₃⁻ and Cl⁻ ions, when compared with concentrations in background groundwater, increase gradually with the distance from the upper area. This result suggests that the water quality in shallow groundwater deteriorates due to contaminant sources at the surface. The contaminations of the major contaminants in groundwater show a positive linear relationship with electrical conductivity, indicating the deterioration in water quality is related to the effects of the contaminants. The relationships between contaminant concentrations, as inferred from the ternary plots, show the contaminant concentrations in organic fertilizer are positively related to concentrations of NO₃⁻, Cl⁻, and SO₄²⁻ ions in the shallow portable groundwaters, which means the fertilizer is the main contaminant source. The results also show that the deterioration in shallow groundwater quality is caused mainly by NO₃⁻ and Cl⁻ derived from organic fertilizer with additional SO₄²⁻ contaminant from livestock wastes. Even though the concentrations of the contaminants within the shallow groundwaters and the contaminant sources are largely variable, it is useful to consider the ratio of contaminant concentrations and the relationship between contaminants in groundwater samples and in the contaminant source when analyzing deterioration in water quality.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.1
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• pp.1-7
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• 2013

The purpose of this study was to provide basic information for breeding cowpeas (Vigna unguiculata L.) by investigating the crop characteristics of 245 accessions of cowpea collected in Korea and abroad. All specimens flowered within 41 to 50 days (51.5%) or 51 to 60 days (43.7%) of sowing and matured 21 to 30 days (53.9%) or 31 to 40 days (23.7%) from flowering. Thus, the total time from sowing to maturity was either 71 to 80 days (26.9%) or 81 to 90 days (23.4%) for all specimens. The accessions were classified into indeterminate type (72.7%), intermediate type (25.7%) and determinate type (1.6%) based on growth; prostrate type (78.8%) and erect type (21.2%) based on plant type; heart shape (98.4%) and lanceolate (1.6%) based on leaflet shape; and purple (85.2%), white (13.6%) and light green (1.2%) based on corolla color. The accessions were classified into brown (54.7%) and yellowish brown (37.6%) based on color at pod maturity; and downward (90.6%), middle (5.7%) and standing upright (3.7%) based on pod setting position. Seed coat color varied as 25.3% were brown, 23.3% were black, and 20.8% were white. Seed shape also varied as 66.9% were egg-shaped, 24.9% were rectangular and 8.2% were kidney-shaped. Pod lengths ranged from 10.1-20.0 cm and from 20.1-30.0 cm in 89.0% and 8.6% of specimens, respectively. There were 12.1-15.0, 9.1-12.0, and 15.1-18.0 seeds per pod in 62.0%, 25.7% and 9.1% of specimens, respectively. The weight of one hundred seeds ranged from 15.1-20.0 g (37.6%) and 10.1-15.0 g (28.6%). Seed yields per plant were 100.1-200.0 g (52.7%), less than 100 g (22.9%), and 200.1-300.0 g (15.9%). The starch content in the seeds of the seven selected resources ranged from 44.1 to 57.0% while the protein content ranged from 23.3 to 27.5% with significant differences. The sucrose content ranged from 1.46 to 2.03%, also with significant differences.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.6
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• pp.21-30
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• 2014

The purpose of this study was to evaluate human thermal comfort in summer by the type of greenery in parks and to explore planning solutions to supply a comfortable thermal environment in parks. The research was conducted in three different land cover types: a park with multi-wide-canopied trees(WOODLAND), park with grass(LAWN) and park with pavement(PAV) as reference sites in Hamyang-Gun SangrimPark. Field measurements of air temperature, relative humidity and wind velocity, short-wave and long-wave radiation from six directions(east, west, north, south, upward and downward) were carried out in the summer of 2014(August 21-23 and 29-30). Mean Radiant Temperature($T_{mrt}$) absorbed by a human-biometeorological reference person was estimated from integral radiation and the calculation of angular factors. The thermal comfort index PET was calculated by Rayman software, UTCI, OUT_SET$^*$ were calculated using the UTCI Calculator and the Thermal Comfort Calculator of Richard DeDear. The results showed that the WOODLAND has the maximum cooling effect during daytime, reduced air temperatures/$T_{mrt}$ by up to $5.9^{\circ}C/35^{\circ}C$ compared to PAV and lowered heat stress values despite increasing relative humidity values and decreasing wind velocity. While the LAWN had very slight cooling effects during daytime, reduced air temperatures/$T_{mrt}$ by up to $0.9^{\circ}C/3^{\circ}C$ compared to PAV, the improvement effects of the thermal comfort index was very slight. However, during nighttime the microclimatic and radiant conditions of WOODLAND, LAWN, and PAV were similar owing to the absence of solar radiation, reduction of wind velocity and an increase in relative humidity. Because the shading and evapotranspiration effects of the WOODLAND were much greater than the evapotranspiration effects of the LAWN, it can be said that the solutions for supplying comfortable thermal environment in parks are to amplify the green volumes rather than green areas. This study was undertaken to evaluate the human thermal comfort in summer of WOODLAND/LAWN parks and to determine the improvement effects of thermal comfort index. These results can contribute to the provision better thermal comfort for park users during park planning.

• Korea journal of population studies
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• v.10 no.1
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• pp.28-38
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• 1987

This paper was set out to study the structure of the career occupational mobility in the early and rapid phase of industrialization in Korea. By analyzing the individual life histories regarding occupational mobility and achievement, I propose a model of yearly career mobility of Korean men and Women during the period of 30 years between 1954 and 1983. With the occupational classification scheme of 5 groups - Upper Nonmanual, Lower Nonmanual, Self Employed, Manual, Farm - the mobility pattern in the person-year mobility table analyzed can be characterized primarily by the strong influence of immobility. The degree of immobility, however, is different by the occupational groups. The absolute amount of immobility can be summarized as being U-shaped. Overall, the pattern of mobility can be explained best by the concept of occupational distance. I then propose a model of relative career occupational mobility pattern that combines the conceptual and theoretical basis and the methodological rigor. The model is based on the notion of the reproduction of inequality, the labor market context, and the life history perspective. The model encompasses the 6 conceptual explanatory factors such as persistence effect, ceiling effect, traditional sector effect, nonmanual occupation effect, alternative mobility channel effect, and occupational distance effect, as well as the effects of both origin and destination occupations. The relative pattern of career mobiliity in Korea can be characterized by the following six findings. First, the persistence effect on the diagonal cells of the mobility table is dominant. Second, a clear evidence of the negative effect of occupational distance between nonmanual occupations and manual and farm occupations is found. Third, the out-mobility from farming took place regardless of the destination occupations. Fourth, the internal mobility within the nonmanual occupation block is high and bi-directional, and is exclusive against other occupations. Fifth, the 'self employed' occupation is serving a peculiar function in both inflow and outflow pattern. Last, the relative pattern of career occupation mobility is asymmetrical in terms of the upward and downward mobility.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.6
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• pp.690-698
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• 2017

Vietnam is a marine nation with more than 3,444 km of shorelines, thousands of islands, and 2,360 rivers and canals of over 42,000 km long. As the frequency and the volume of oil transportation by ships increase, the possibility of oil spill incidents becomes higher than ever. Fuel oil and cargo oil spills at sea have widespread impact and long-term consequences on marine ecosystems, coastal resources and human health as well as socio-economy. This study is to show not only the present state of marine oil spills in Vietnam such as the number and the volume of oil spills for two decades, and an overall about Vietnamese national response system like national framework for Oil Spill Response (OSR), etc. but also to present the recommendations for enhancing national capability in response to oil spill incidents in Vietnam, especially, with a comparison of national OSR systems between Vietnam and South Korea. As the result, the number and the volume of marine oil spills in Vietnam showed an upward trend as opposed to a downward trend in South Korea. This means that Vietnam has the possibility of oil spills in coastal waters. Therefore, three main recommendations for the enhancement of national OSR capability in Vietnam are proposed as follows: (1) the development of alternative plan for reenforcing national OSR system involving legal system for preparedness and response to oil spill pollution such as the acceptance and implementation of OPRC Convention as well as the establishment of national fund compensating for the damage and loss caused by oil pollution; (2) the enhancement of a consistent reporting, alerting and monitoring system; and (3) the development of training and exercise programs with standard contents of educational courses.

• The Journal of the Petrological Society of Korea
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• v.28 no.2
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• pp.111-128
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• 2019

Ulleung Island is the top of an intraplate alkalic volcano rising 3200 m from sea floor in the East Sea (or Sea of Japan). The emergent 984.6 m consist of eruptive products of basaltic, trachytic and phonolitic magmas, which are divided into Dodong Basaltic Rocks, and Ulleung, Seonginbong and Nari groups. The Maljandeung Tuff in the Nari Group consists of thick pyroclastic sequences which are subdivided into 4 members (N-5, U-4, 3, 2), generating from explosive eruptions during past 18.8~5.6 ka B.P. From chemical data, the Member N-5, phonolitic in composition, is considerably enriched in incompatible elements and REE patterns with significant negative Eu anomalies. The members 4, 3 and 2 are phonolitic to tephriphonolitic in composition, and their REE patterns do not have significant Eu anomalies. In variation trend diagrams, many elements show abrupt compositional gaps between members, and gradual upward-mafic variations from phonolite to tephriphonolite within each member. It suggests a downward-mafic zonation that were evolved into phonolitic zone in the lower part to tephriphonolitic zone in upper part of magma chamber. It is supposed that the chemical stratification generated from multiple mechanisms of thermal gravidiffusion, crystal fractionation, and gradual melting and sequential emplacement. The stratified magmas were explosively erupted to generate a small caldera during short period (11 ka B.P.). Especially both members (U-3, 2) were accumulated by gradually erupting from the upper phonoltic zone to the lower tephriphonoltic zone of the stratified chamber in 8.4 ka B.P. and 5.6 ka B.P. time, respectively.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.347-354
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• 2018

In order to setting the control standard of Chinese cabbage pests using a drone, the downward wind speed, spraying width, and the number of falling particles and particle size were examined using a water sensitive paper with spray different heights (3, 4, 5 m) and flying speeds (3, 4 m/sec). Fore kinds of pesticides for aviation control were used to test the perfect lethal concentration and dose for major pests of Chinese cabbage such as Plutella xylostella, Spodoptera exigua and Spodoptera litura. The number of falling particles in spraying pesticides with drones was 80.5% on the upper side, 14.8% on the vertical side, and 4.7% on the back side. The number of falling particles as different spray heights were 3 m = 53, 4 m = 40 and $5m=39particles\;cm^{-2}$. The number of falling particles as different flying speeds were $3m\;sec^{-1}=62$ and $4m\;sec^{-1}=25particles\;cm^{-2}$. In the laboratory test, the perfect lethal concentration and dose of Plutella xylostella was chlorfenapyr SC (20 times, $0.5{\mu}l$) and bistrifluron chlorfenapyr SC (25 times, $0.5{\mu}l$). The perfect lethal concentration and dose of Spodoptera exigua was chlorfenapyr SC (20 times, $1{\mu}l$), bistrifluron chlorfenapyr SC (20 times, $1{\mu}l$), and chlorfenapyr SC (20 times, $1{\mu}l$) and bistrifluron chlorfenapyr SC (20 times, $0.5{\mu}l$) for Spodoptera litura. Therefore, the main pest control method of Chinese cabbage using drones is 20 times diluted chlorphenapyr SC or bistrifluoruron-chlorphenapyr SC, sprayed at 3 m height by $3msec^{-1}$ of going speed. This spraying method will be effective for control of Chinese cabbage pest.

• Korean Journal of Environment and Ecology
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• v.33 no.4
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• pp.440-446
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• 2019

This study examined the growth and fruiting characteristics and the acorns biomass allometric equation of Quercus acuta to provide reference data related to the growth and seed supply during the restoration of evergreen forest in the warm temperate zone in Wando Island, Korea. For the growth survey, we selected and cut three sample trees having a mean diameter at breast height (DBH) to investigate the growth analysis through a stem analysis. We then developed the allometric equation (Y=aX+b) of DBH and tree height growth characteristic (Y) according to the average tree age (X) of sampled trees and estimated the DBH and tree height according to the age of Quercus acuta. For the fruiting survey, we selected and cut three sample trees with full fruit in August when, they are at the early mature fruiting stage, for the analysis. To develop the acorns/tree biomass allometric equation of Quercus acuta, we selected and cut ten sample trees of evenly divided diameters. The acorns biomass allometric equation ($Y=aX^b$) was derived by analyzing the biomass (Y) and the growth characteristics (X), such as the DBH, tree height, crown width, and crown height. The allometric equations of average tree age according to DBH and tree height were Y=0506X-2.064 ($R^2=0.999$) and Y=0.321X+0689 ($R^2=0.992$), respectively. The developed allometric equations estimated that the DBH were 3.0cm, 8.1cm, 13.1cm and 18.2cm while the tree heights were 3.9m, 7.1m, 10.3m, and 13.5m when the tree ages were 10, 20, 30, and 40 years, respectively. The analysis results of fruiting characteristics showed that the length, the diameter, the number of fruits, and the number of acorns per fruiting branch had the statistically significant difference and tended to decrease from the upper part to the lower part of crown downward. The total number of acorns was 1,312 acorns/tree in the upper part, 115 acorns/tree in the middle part, and 5 acorns/tree in the lower part of the crown. The allometric equation for the amount of acorns with DBH as an independent variable was $Y=0.003X^{4.260}$ with the coefficient of determination at 0.896. Although the coefficient of determination of the allometric equation using only DBH as the independent variable was lower than that using DBH and tree height ($D^2H$), it would be more practical to consider only DBH as the independent variable because of measurement errors.

• The Journal of the Petrological Society of Korea
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• v.28 no.1
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• pp.1-13
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• 2019

The characteristics of the rock cleavage of Jurassic Geochang granite were analysed using the parameters from the length and spacing-cumulative frequency diagrams. The evaluation for three planes and three rock cleavages was performed using the 25 parameters such as (1~2) slope angle(${\alpha}^{\circ}$and ${\beta}^{\circ}$), (3) intersection angle(${\alpha}-{\beta}^{\circ}$), (4) exponent difference(${\lambda}_S-{\lambda}_L$), (5~12) length of line(oa, ob, ol, os, ss', ll' and sl') and (13~15) length ratio(ol/os, ss'/ll' and ll'/sl'), (16) mean length((ss'+ll')/2), (17~23) area (${\Delta}oaa^{\prime}$, ${\Delta}obb^{\prime}$, ${\Delta}obb^{\prime}$, ${\Delta}oaa_a^{\prime}$, ${\Delta}obb_a^{\prime}$, ${\Delta}ll^{\prime}s^{\prime}$, ${\Delta}ss^{\prime}l^{\prime}$ and ⏢$ll^{\prime}ss^{\prime}$) and (24~25) area difference(${\Delta}obb^{\prime}-{\Delta}oaa^{\prime}$ and ${\Delta}obb_a^{\prime}-{\Delta}oaa_a^{\prime}$). Firstly, the values of the 11 parameters(group I: No. 1, 3~4, 7, 9~10, 13, 15~16, 20 and 25), the 3 parameters(group II: No. 5, 8 and 17) and the 2 parameters(group III: No. 12 and 22) are in orders of H(hardway) < G(grain) < R(rift), R < G < H and G < H < R, respectively. On the contrary, the values of parameters belonging to the above three groups show reverse orders for three planes. Secondly, the generalized chart for three planes and three rock cleavages were made. From the related chart, the distribution types formed by the two diagrams related to lengths and spacings were derived. The diagrams related to spacings show upward curvature in the chart of rift plane(G1 & H1, R') and hardway(H1 & H2, H). On the contrary, the diagrams related to lengths show downward curvature. These two diagrams take the form of a convex lens in the upper section. Besides, the two diagrams cross each other in the lower section. The overall shape formed by the above two diagrams between three planes($H^{\prime}{\rightarrow}G^{\prime}{\rightarrow}R^{\prime}$) and three rock cleavages($R{\rightarrow}G{\rightarrow}H$) display in reverse order. Lastly, these types of correlation analysis is useful for discriminating three quarrying planes.