• Journal of the Korean Institute of Landscape Architecture
• /
• v.29 no.3
• /
• pp.38-45
• /
• 2001

This study quantified annual $CO_2$, SO$_2$ and NO$_2$ uptake and annual $O_2$ production by trees in Yongin´s urban ecosystem, and explored values of urban tree plantings in atmospheric purification. Woody plant cover was only 7.7% with planting density of 1. trees/100$m^2$, and the tree-age structure was largely characterized by a young, growing tree population. Annual per capita pollutant emissions from fossil fuel consumption were 7.3t/yr for $CO_2$, 7.6kg/yr for SO$_2$, and 26.6kg/yr for NO$_{x}$. Carbon dioxide storage per unit urban area by trees was 13.1t/ha and the economic value for $CO_2$ storage was ￦6.6millions/ha. Annual atmospheric purification was 2.0t/ha/yr for $CO_2$ uptake, 2.0kg/ha/yr for SO$_2$ uptake, 4.0kg/ha/yr for NO$_2$ uptake and 1.5t/ha/yr for $O_2$ production, and the annual economic value for the atmospheric purification was ￦1.5millions/ha/yr. Urbantrees stored an amount of $CO_2$ equivalent to about 3.1% of the total annual $CO_2$ emissions, and annually offset total $CO_2$ emissions by 0.5%. Annual SO$_2$ and NO$_2$ uptake by trees equaled 0.5% of total SO$_2$ emissions and 0.3% of total NO$_{x}$ emissions, respectively. Urban trees also played an important role through producing annually 9.2 of the $O_2$ requirement for Yongin´s total population, despite relatively poor tree plantings. Future active plantings and greenspace enlargement in the study city could enhance the role of atmospheric purification by urban trees. The results from this study are expected to be useful in emphasizing environment benefits of urban trees, and in urging the continuous necessity for tree planting and management budget.get.

• The Journal of Engineering Geology
• /
• v.27 no.3
• /
• pp.313-322
• /
• 2017

The purpose of this study is to estimate the surface and subsurface flows through the modelling of the model area and facility agricultural complex, and to calculate the groundwater recharge rate through water budget analysis. From results of surface flow modeling, the surface water is flowed to a depth of about 1 to 5 meters from the upper region (northeast) to the lower region (southeast) of the Miryang River. At the M01 point (upper), the observed surface water flux and the model surface water flux are consistent. At the M02 points (lower), the observed surface water flux and the model surface water flux are a difference of 1%. From results of subsurface flow modeling, the depth of groundwater is similar to elevation in the river and higher to the forest area. Ground water depth considering groundwater pumping is that the model values appears higher than the observed values to be within 1.5 m. From results of surface-subsurface integrated modeling, the groundwater recharge area is estimated about 90% of the model area, and the groundwater recharge rate is estimated $1.92{\times}10^5m^3/day$. From results of annual water budget analysis, the groundwater recharge rate per unit area is estimated to be 503.9 mm/year, and average annual rainfall is estimated at around 39%.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.38 no.2
• /
• pp.140-148
• /
• 2002

The primary goal of this study is to determine the distribution characteristics using a scientific echo sounder in the Yellow Sea west of South Korea. The survey was carried out between 33$^{\circ}$00'N~37$^{\circ}$00'N latitude and 124$^{\circ}$00'E~126$^{\circ}$00'E longitude during the months of May and August, 1999 and April, 2000. The ships used in this survey were the R/V Chung-kyeong(G/T 300) and R/V Dong-baek(G/T 1,050) of Yeosu National University. The results obtained are as follows : 1. From the oceanographic data the Yellow Sea were divided into three sea areas which were the western waters of Chejudo, Mokpo and Kunsan. The oceanographic conditions were different in each of these three areas and the western waters of Chejudo were higher about 1~5$^{\circ}C$ more than the western waters of Gunsan. Generally, thermoclines were presented clearly in all three areas, but more so in August than in May according to seasons. 2. The horizontal distribution of S$_{A}$(area backscattering coefficient per unit area) value is that the western sea waters of Chejudo area are higher than that of the western sea waters of Mokpo and Gunsan. 3. The vortical distribution of S$_{A}$ value varies with thermocline that the harder thermocline is, the higher the S$_{A}$ value is. 4. The S$_{A}$ values on the types of biomass distribution are different with frequency. At the 38kHz, the demersal schools have higher values than the pelagic schools. At the 120kHz, the pelagic schools have higher values than the demersal schools.

• Fashion & Textile Research Journal
• /
• v.1 no.3
• /
• pp.280-287
• /
• 1999

The aims of this research were to study on the relationship between the mechanical properties and the deformation behavior of weft-knitted fabrics as a function of knit structure and knit density. Eighteen weft-knitted fabrics were produced with six different knit structures ($1{\times}1$ rib, half-cardigan rib, half-milano rib, interlock, single-pique, and crossmiss interlock) and three different knit densities (loose, medium, tight). The mechanical properties of these samples were measured using the KES-F system. The 2HBIW increased as knit density was raised. The increase was greater for the double knit fabrics in all samples. Half-milano rib and crossmiss interlock samples showed the lowest 2HG/G values. The double knits were smaller than those of single knits indicate a higher degree of surface smoothness. The ratio of compression energy to weight per unit area of the double knits had lower values than the single knits.

• Proceedings of the Korea Society of Environmental Toocicology Conference
• /
• 2003.10a
• /
• pp.170-170
• /
• 2003

An initial study has been conducted with Korea Institute of Geoscience and Mineral resources and National Institute of Environment Research to evaluate the distribution of radon levels and their risk levels of groundwater in Korea. Probability distribution of 616 samples was log-normal one with 1,867pCi/L as arithmetic value, 920pCi/L as median and 40,010pCi/L as maximum during iou. years(1999-2002). In addition, 10% of total samples are in excess of 4,000pCi/L, 20% in excess of 2,700pCi/L, and 30% in excess of 1,700pCi/L, and 15 samples exceeds 10,000pCi/L. Total samples are grouped into 10 areas and 5 rocks unit, and difference of concentrations among areas and rocks are statistically significant(respectively, p<0.0001). The highest area is Daejeon located in ogcheon metamorphic rocks and granitic rocks, and most of all sites with high concentration sites are located in granitic rocks. The lowest area is Jeju located in volcanic rocks. We have estimated excess cancer risks of radon based on these data. To estimate risks, first of all, use patterns of groundwater are categorized with 6 groups: for drinking, household, farming, washing cars, raising stock, and others. We considered risk only for drinking water and household water because radon is rapidly dispersed before it of other use reach human respiratory organs. We select 565 samples for risk analysis, and applied unit risk which is 6.6210-7 per pCi/L to be recommended by NAS committee. Unit risk was derived from considering radon ingestion and radon inhalation from water use. When estimating risk, we analyzed PDF of concentration and represented risk as 50 and 95 percentile values to consider uncertainty with Monte-Carlo simulation. It results in 10-4 level of their excess cancer risk and in 10-2 level in some areas with high concentration of radon. It must be monitor periodically and take adequate actions in these risky sites. We recommend that it needs to take more survey and finally set guideline for radon regulation in groundwater.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.23 no.4
• /
• pp.192-203
• /
• 2018

The surfgrass Phyllospadix iwatensis is native in the exposed rocky shores of the Northwestern Pacific Ocean. In Korea, P. iwatensis is mainly found on the rocky subtidal zone in the central eastern coast. In this study, to examine the ecological characteristics of P. iwatensis, we investigated changes in morphological characteristics, density, biomass, and leaf productivity as well as changes in the underwater irradiance and water temperature of its habitat monthly from August 2017 to July 2018. Underwater irradiance and water temperature showed clear seasonal changes; increases in spring and summer and decreases in fall and winter. Morphological characteristics, shoot density, biomass, and leaf productivities of P. iwatensis exhibited significant seasonal variations, increasing in winter and spring and decreasing in summer and fall months. P. iwatensis leaf productivities both per shoot and per unit area showed significant positive correlations with underwater irradiance. The average leaf productivity of P. iwatensis per area was $6.3{\pm}1.3g\;m^{-2}d^{-1}$, while minimum and maximum values were $2.4{\pm}0.3g\;m^{-2}d^{-1}$ in February 2018 and $16.4{\pm}4.4g\;m^{-2}d^{-1}$ in May 2018, respectively. The optimum water temperature for the growth of P. iwatensis in this study was between $12-13^{\circ}C$.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.5
• /
• pp.693-698
• /
• 2024

As there are various types of discontinuities developing along with various rock types, the orientation and density of each type of discontinuities were measured to analyze the behavior of groundwater within the rock mass. Among the orientations of discontinuities, the strike was measured in azimuth and expressed as a discontinuity trajectory, and the density of discontinuities was quantified as the sum of the lengths of discontinuities developed per unit area. The overall discontinuity trajectory in the study area is predominantly in the northeast direction, the north-south and east-west directions are dominant in the igneous rock distribution area, and the east-west and northeast directions are dominant in the sedimentary rock distribution area. Among the types of discontinuities, they show discontinuity trajectories similar to the northeast direction, which is the dominant orientation of stratum boundaries, stratification, and foliation. The discontinuity density ranges from 0.1 m^-1 to 1,000 m^-1. The density distribution of discontinuities was expressed in the form of discontinuity contour diagrams. As a result, the crushed rock near Demiseam in the southern and southwestern part of the study area, the igneous rock area around Maryeong-myeon, the igneous rock area near Yongdam Dam in the northeast, and the igneous rock area near Unilam and Banilam in the northwest showed the highest density of discontinuities at over 100m^-1., the sedimentary rock area near Maisan Mountain showed relatively low values. It suggests that the results of geophysical exploration and drilling survey data in the existing study area, as well as the geological structure and density and trajectory of discontinuities, may be important factors in the behavior of groundwater in rock mass in the future.

• Journal of Korean Society of Forest Science
• /
• v.103 no.4
• /
• pp.696-702
• /
• 2014

This study was conducted to provide resonable price of timber that come out from certified forests for sustainable forest management. To accomplish this study objectives, we analyzed compound interest method, willingness to pay (WTP) and price sensitivity measurement (PSM) when buying certified pulp. In case of compound interest method, we used prime cost by average price per ha of each area (Hongcheon, Inje, Shinnam) and unit price that add up the pulp price and investment costs. Interest rate reflects 2 to 6% and investment period apply to 5 years. WTP and PSM data were collected from questionnaire survey. As a result, if apply to interest rate of 2% and investment period of 3 years, result values are quite similar to WTP of 5% and optimal pricing point of PSM. That also showed similar pattern in each area.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.6
• /
• pp.960-968
• /
• 2015

This study examined the spatiotemporal distribution of demersal fish aggregations in the Northern East China Sea by conducting a trawl survey with hydroacoustic devices. A bottom trawl was used for this survey and fish density was determined from the catch data. Acoustic data were collected at frequencies of 38 and 200 kHz from November to December 2014 and converted into the nautical area scattering coefficient (NASC, $m^2/n{\cdot}mile^2$). In the catch data analysis, the range of catch per unit area by station was $26-8,055kg/km^2$ and for the acoustic data, that of the NASC was $0.45-34.80m^2/n{\cdot}mile^2$. The values were significantly correlated. The combined results of both surveys found that the density was highest at St. 5 ($33^{\circ}$ 10.3', $126^{\circ}$ 23.3') and lowest at St. 8 ($33^{\circ}$ 20.7', $127^{\circ}$ 36.3'). The application of hydroacoustic methods offers a new approach for estimating the biomass of demersal fish aggregations.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.54 no.6
• /
• pp.1030-1035
• /
• 2021

Diving fishermen are demanding permission to use an inspirator that can efficiently catch Manila clam; however, coastal fishermenargue that the use of inspirator devastates the seabed and depletes fishery resources. Therefore, the aim of this study was to evaluate the fishing power of diving gears and its effect on coastal fishing grounds. The average time taken to fish in the seabed (4 m²) with a rake, water gun, and an inspirator was 11.17 min, 13.33 min and 7.81 min, respectivelyThe values of catch per unit time with a rake, water gun, and an inspirator were 3.35 kg/min, 2.26 kg/min, and 3.83 kg/min, respectively. Suspended sediments were observed the most in the water gun fishing area, and were observed more in April when fishing was not carried out than in February when fishing was carried out. However, the difference in the amount of sediment deposited in the fishing area using the three-fishing gears was very small. For an accurate analysis of the impact of the fishing gears on the seabed, supplementary tests such as grain size analysis and changes in benthic organisms need to be conducted.