• The Journal of Engineering Geology
• /
• v.16 no.1 s.47
• /
• pp.69-83
• /
• 2006

This study aims to evaluate a complex groundwater flow system around the underground oil storage caverns using the concept of hydraulic compartment. For the hydrogeological analysis, the hydraulic testing data, the evolution of groundwater levels in 28 surface monitoring boreholes and pressure variation of 95 horizontal and 63 vertical water curtain holes in the caverns were utilized. At the cavern level, the Hydraulic Conductor Domains(fracture zones) are characterized one local major fracture zone(NE-1)and two local fracture zones between the FZ-1 and FZ-2 fracture zones. The Hydraulic Rock Domain(rock mass) is divided into four compartments by the above local fracture zones. Two Hydraulic Rock Domains(A, B) around the FZ-2 zone have a relatively high initial groundwater pressures up to $15kg/cm^2$ and the differences between the upper and lower groundwater levels, measured from the monitoring holes equipped with double completion, are in the range of 10 and 40 m throughout the construction stage, indicating relatively good hydraulic connection between the near surface and bedrock groundwater systems. On the other hand, two Hydraulic Rock Domains(C, D) adjacent to the FZ-1, the groundwater levels in the upper and lower zones are shown a great difference in the maximum of 120 m and the high water levels in the upper groundwater system were not varied during the construction stage. This might be resulted from the very low hydraulic conductivity$(7.2X10^{-10}m/sec)$ in the zone, six times lower than that of Domain C, D. Groundwater recharge rates obtained from the numerical modeling are 2% of the annual mean precipitation(1,356mm/year) for 20 years.

• The Korean Journal of Pesticide Science
• /
• v.13 no.3
• /
• pp.190-196
• /
• 2009

The residues of abamectin 1.8% EC, resisted for control of pine wood nematode, Bursaphelenchus xylophilus in pine tree were surveyed in tissue of Pinus thunbergii and P. koraiensis after injection of a liquid formulation. Limits of detection of abamectin in tissue of P. thunbergii were $0.05\;mg\;kg^{-1}$ and mean recoveries at $0.5\;mg\;kg^{-1}$ trunk injection were 90.9% and 93.1% respectively in stem and trunk of P. thunbergii. Abamectin 1.8% EC, trunk injected in 15 m height P. thunbergii were detected in all stem (edible part of carrier insect of pine wood nematode, Monochamus alternatus) from 0.29 to $0.73\;mg\;kg^{-1}$ after 150 days injection. Amount of residue of abamectin 1.8% EC in 12.6 cm mean breast height diameter (DBH) P. thunbergii were variable depending on individual trees in natural forest. Amount of residues in lower and middle part of trunk were reduced with the passage of the injection time. In upper part of trunk were detected $1.84\;mg\;kg^{-1}$ on 30 days after injection however $0.65\;mg\;kg^{-1}$ on 15 days after injection and under detection limit on 100 and 180 days after injection in P. thunbergii. Bottom and middle parts of crown were detected $0.183\;mg\;kg^{-1}$ and $0.173\;mg\;kg^{-1}$ respectively on 180 days after injection in P. thunbergii. Mean residues of abamectin in crown and trunk were $0.80\;mg\;kg^{-1}$ and $0.30\;mg\;kg^{-1}$ on 170 days after trunk injection in 20 cm DBH and 9 m height P. koraiensis. Mean residues of abamectin in crown and trunk were $0.67\;mg\;kg^{-1}$ and $0.36\;mg\;kg^{-1}$ on 170 days after trunk injection in 15 cm DBH and 6 m height P. koraiensis.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.28 no.4
• /
• pp.143-157
• /
• 2023

This study confirmed the characteristics of macrobenthic community due to anthropogenic environmental changes in the Boryeong Jugyo tidal flat, where the habitat of manila clam (Ruditapes philippinarum) and mud shrimp (Upogebia major) is separated. The total number of occurring species was 55 during the study period with an average habitat density of 338 ind./m² and a biomass of 212.2 gWWt/m². The number of occuring species increased from 27 species at the upper flat to 37 species at the lower flat, and the dominant species differed by tide levels (Upper: Leonnates persica, Middle: Heteromastus filiformis, Lower: R. philippinarum). The macro-benthic community sturctures of the top 10 species using cluster analysis and nMDS were divided into two groups, focusing on Manila clam culture farm of lower flats and middle flats with high habitat density, reflecting the influence of specific species. The sediment composition of the U. major habitat space fluctuated highly, but it was maintained annually, and the sorting coefficient was 2.1 𝜑, and the proportion of the same particle size was increased. In particular, because the middle flat has a dense anthropogenic impact, a dominant species, H. filiformis dominated and revealed a relationship with the density of burrow holes of U. major, which is considered to be a biological interaction between these two macrofauna in this tidal flat.

• Journal of the Korean earth science society
• /
• v.35 no.7
• /
• pp.537-542
• /
• 2014

The Gravity Recovery and Climate Experiment (GRACE) has observed the Earth's mass redistribution mainly caused by the variations of groundwater, ice sheet, and sea level since its launch in April 2002. The global gravity model estimated by the GRACE observation is corrected by barometric pressure, and thus represents the change of Earth mass on the Earth's surface and below Earth's surface excluding air mass. However, the total air mass varies due to the water exchange between the Earth's surface and the atmosphere. As a result, the nominal GRACE gravity model should include the Earth's gravity spectrum associated with the total air mass variations, degree 0 and order 0 coefficients of spherical harmonics ($C_{00}$). Because the water vapor content varies mainly on a seasonal time scale, a change of $C_{00}$ (${\delta}C_{00}$) is particularly important to seasonal variations of sea level, and mass balance between northern and southern hemisphere. This result implies that ${\delta}C_{00}$ coefficients should be accounted for the examination of continental scale mass change possibly associated with the climate variations.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.351-351
• /
• 2013

한국 전체 에너지 사용량 중약 24%의 에너지가 건축물 부분에 소비되고 있다. 건축물의 벽체나 유리창 등을 통해서 에너지 손실이 이루어지는데 유리창은 벽체에 비해 약 10배 이상 낮은 단열 특성을 가지고 있기 때문에 유리창을 통한 열손실량은 더 크다. 이러한 유리창 부분의 열손실 문제를 해결할 수 있는 방안으로 좋은 단열 특성 및 낮은 방사율을 가지고 있는 Low-e coating 방법을 사용하였다. 본 실험에서는 XG glass 기판 위에 IGZO/Ag/IGZO OMO 구조의 다층 박막을 증착하였다. RF magnetron sputtering방법을 이용하여 OMO 구조의 상부와 하부의 Oxide layer로 IGZO 박막을 증착하였다. 사용된 IGZO 타겟은 $In_2O_3$ (99.99%), $Ga_2O_3$ (99.99%), ZnO (99.99%)의 분말을 각각 1:1:1 mol% 조성비로 혼합하여 소결하여 제작하였다. Thermal Evaporator 장비를 이용하여 OMO 구조의 Metal layer로 Ag (99.999%)를 증착하였다. 실험 기판은 크기 $30{\times}30mm$의 0.7T XG glass를 사용하였다. OMO 구조의 산화층 IGZO 박막은 상/하층 동일 조건으로 기판 온도는 실온으로 고정하였으며, 초기 압력 $3.0{\times}10^{-6}$ Torr, 증착 압력 $3.0{\times}10^{-2}$ Torr, RF 파워 50W, Ar 유량 50 sccm로 고정시키고 증착 시간이 변화하면서 박막을 증착하였다. OMO 구조의 Metal layer로 Ag 증착 조건은 초기 진공도가 약 $6.0{\times}10^{-6}$ Torr 이하로 유지하고 기판을 2 Rpm의 속도로 회전시켰다. 이후 0.3 V로 Ag를 10분간 가열하여 충분히 녹인 후 Film Thickness Monitor로 두께를 확인하였다. OMO 다층 박막의 산화물층 변화에 따라 로이다층 박막의 구조적, 광학적 및 전기적 특성을 분석하였다. XRD 분석결과에 의하여 Bragg's 법칙을 만족하는 피크가 나타나지 않는 비정질 구조임을 확인할 수 있으며, AFM 분석결과에 통해서 최소 1.3 nm의 Roughness를 나타내었다. UV-Visible-NIR 분광광도계를 이용하여 다층 박막은 가시광선 영역에서 평균 80%의 광 투과성을 보여 IR 영역에서 평균 30% 투과하고 좋은 차단 특성을 나왔다. Low-e 특성을 갖는 유리창을 통해서 에너지 절약을 이룰 수 있는 것을 확인할 수 있었다.

• Journal of the Korean Geotechnical Society
• /
• v.25 no.5
• /
• pp.17-28
• /
• 2009

When embankments are constructed on soft clay deposit, unsymmetrical surcharges due to embankments may generate the excessive vertical settlement and lateral deformation of soft clay foundation. The excessive deformations in soft grounds cause not only stability problem of the embankment itself but also that of the adjacent structures. The objectives of this research are to study the deformational behavior of soft ground due to the embankment load with different loading and soil conditions. Five model tests are carried out with different test conditions. From the results of the model tests, it is concluded that the lateral displacement induced by the embankment load occurs in the range of two times of the embankment width from a toe. In addition, the relationship between loading rate, v, and the vertical settlement of the soft ground, ${\Delta}s$, and the lateral displacement at the toe of embankment, ${\Delta}y_m$, is investigated based on the model test results.

• Journal of Astronomy and Space Sciences
• /
• v.25 no.4
• /
• pp.405-414
• /
• 2008

To better understand the physical processes that control the high-latitude lower thermospheric dynamics, we analyze the divergence and vorticity of the high-latitude neutral wind field in the lower thermosphere during the southern summertime for different IMF conditions. For this study the National Center for Atmospheric Research Thermosphere-Ionosphere Electrodynamics General Circulation Model (NCAR-TIEG CM) is used. The analysis of the large-scale vorticity and divergence provides basic understanding flow configurations to help elucidate the momentum sources that ulti-mately determine the total wind field in the lower polar thermosphere and provides insight into the relative strengths of the different sources of momentum responsible for driving winds. The mean neutral wind pattern in the high-latitude lower thermosphere is dominated by rotational flow, imparted primarily through the ion drag force, rather than by divergent flow, imparted primarily through Joule and solar heating. The difference vorticity, obtained by subtracting values with zero IMF from those with non-zero IMF, in the high-latitude lower thermosphere is much larger than the difference divergence for all IMF conditions, indicating that a larger response of the thermospheric wind system to enhancement in the momentum input generating the rotational motion with elevated IMF than the corresponding energy input generating the divergent motion. the difference vorticity in the high-latitude lower thermosphere depends on the direction of the IMF. The difference vorticity for negative and positive $B_y$ shows positive and negative, respectively, at higher magnetic latitudes than $-70^{\circ}$. For negative $B_z$, the difference vorticities have positive in the dusk sector and negative in the dawn sector. The difference vorticities for positive $B_z$ have opposite sign. Negative IMF $B_z$ has a stronger effect on the vorticity than does positive $B_z$.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.22 no.4
• /
• pp.258-267
• /
• 2020

The agrivoltaic can produce electricity and grow crops on fields at the same time. It is necessary to analyze the cultivation environment and evaluate the crop productivity under agrivoltaic because the shading point changes according to structure of agrivoltaic and sun's position. Two types of "fixing" and "tracing" agrivoltaic were installed, and a rice cultivation experiment was conducted in the fields under each agrivoltaic and without shading (control). "Hyunpoombyeo" was transplanted on June 7, 2019, and grown with fertilization of 9.0-4.5-5.7 kg/10a (N-P-K). Fifteen weather stations were installed under each agrivoltaic to measure solar radiation and temperature, and yield and yield-related elements were investigated by points. The accumulated solar radiation during the rice growing season in fixing was no much difference between points, and that in tracing was much difference between points. However, the average solar radiations of two agrivoltaics were similar. The mean temperature, yield, and yield-related elements showed a significant difference for the shading rate, and decreased with increasing the shading rate except ripening grain rate and 1000 grain weight of fixing agrivoltaic. In the relationship between shading rate and yield, fixing and tracing were fitted to a logistic equation and a simple linear equation, respectively, and showed a high correlation (tracing: R2 = 0.62, fixing: R2 = 0.73). The shading rate variation by point for two types was large despite similar yield variation. Thus, it needs to be more closely examined the relationship of the shading rate for a specific period rather than the shading rate during the whole growing season.

• Nuclear Medicine and Molecular Imaging
• /
• v.42 no.5
• /
• pp.375-382
• /
• 2008

A low iodine diet (LID) is the recommended preparation for radioactive iodine treatment. However, the recommended duration and stringency of LID are different among each recommendation. More stringent LID is expected in Korea because Korea is a iodine-rich region. We investigated the decrement of urine iodine excretion by two-week stringent LID for remnant thyroid ablation with radioactive iodine in Korean patients with thyroid cancer, prospectively. Material and Method: From November 2006, patients who referred to our hospital for remnant ablation after total thyroidectomy were included in this study. To decrease total body iodine, our protocol included three strategies. First, we checked medication which could inhibit the radioactive iodine uptake. Second, the date of 1-131 treatment was scheduled at least 3 months later if contrast agent had been used. The last strategy was two-week stringent LID education by specialized nutritionist. Before and after two-week stringent LID, 24hr-urine iodine was analyzed respectively. 24hr-urine creatinine was also analyzed for determining more valid 24hr urine sampling subgroup. Results: Total 51 patients were finally enrolled. Average of 24hr-urine iodine excretion was significantly lowered ($787{\pm}2242\;{\rightarrow}\;85{\pm}85\;{\mu}g/d$, p=0.03) after LID and 74.4% of patients reached below the recommended urine iodine excretion level ($<100\;{\mu}g/d$). In subgroup (n=14), similar results was showed ($505{\pm}666\;{\rightarrow}\;99{\pm}116\;{\mu}g/d$, p=0.05) and 78.6% of patients met the criteria. Conclusion: Most patients could reach below the recommended urine iodine level after two-week stringent LID. Therefore, in our opinion, at least two-week stringent LID should be recommended in Korea.

• Journal of Nutrition and Health
• /
• v.26 no.5
• /
• pp.615-624
• /
• 1993

The body fat distribution and nutritional state of the Korean and Japanese young female subjects were compared. Three-day individually weighed, dietary intakes and anthropometric measurements were determinded in 48 Korean and 60 Japanese female students. 19 to 23 yr of age, from the divisions of nutritions. The body composition estimates were measured by bioeletrical impedance-total body water(BI-TBW) method. There were no significant difference between the Korean and Japanese young females in body size and body shape. The Korean young females had lower estimated total body fat and internal fat that calculated by BI-TBW method, but there was no great difference between the Korean and the Japanese in subcutaneous fat. In contrast, the Korean young females are reported to have the same total energy expenditure per day as the Japanes young females and the total energy intakes and carbohydrate energy intake ratio per day were significantly higher than those of the Japanese young females. The difference in body fat distribution and energy intakes in Korean, and the role of capsaicin in red pepper are discussed as a possible determinant of the internal fat in the Korean vs the Japanese.