• Journal of the Korean earth science society
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• v.45 no.3
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• pp.192-202
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• 2024

Ocean reanalysis data are extensively used in ocean circulation and climate research by integrating observational data with numerical models. This approach overcomes the spatial and temporal limitations of observational data and provides high-resolution gridded information that considers the physical interactions between ocean variables. In this study, I extended the previously produced 12-year (2011-2022) Northwest Pacific regional ocean reanalysis data to create a long-term reanalysis dataset (K-ORA22E) with a horizontal resolution of 1/24° spanning 30 years (1993-2022). These data were analyzed to diagnose long-term ocean climate change in the Korean marginal seas. Analysis of the K-ORA22E data revealed that the axis of the Kuroshio extension has shifted northward by approximately 6 km per year over the past 30 years, with a significant increase in sea surface temperature north of the Kuroshio axis. Among the waters surrounding the Korean Peninsula, the East Sea exhibited the most significant temperature increase. In the East Sea, the temperature increase was more pronounced in the middle layer than in the surface layer, with the East Korea Warm Current showing a rate two to three times higher than the global average. In the central Yellow Sea, where the Yellow Sea Bottom Cold Water appears, temperatures increased over the long-term, but decreased along the west and south coasts of the Korean Peninsula. These spatial differences in long-term temperature changes appear to be closely related to the heat transport pathways of warm water from the Kuroshio Current. High-resolution regional ocean reanalysis data, such as the K-ORA22E produced in this study, are essential foundational data for understanding long-term variability in the Korean marginal seas and analyzing the impacts of climate change.

• Korean Journal of Ichthyology
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• v.36 no.3
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• pp.288-294
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• 2024

A juvenile of long-snout tonguefish, Symphurus longirostris belonging to the family Cynoglossidae, was collected from the waters around Jeju Island, Korea in August 2023. Molecular analysis revealed that our juvenile specimen was identical to S. longirostris adult from Japan (Kimura-2-parameter distance, d=0.002) based on mitochondrial DNA 16S ribosomal RNA region sequences 475 base pairs, and differed from its congeneric S. orientalis (d=0.199). The juvenile of S. longirostris has the following morphological traits: obvious dermal spots on both sides of the bases of the dorsal and anal fins; and peritoneum bluish black on its dorsalmost aspect. The juvenile of S. longirostris is also distinguished from S. orientalis in that they do not have a patch of melanophores above the abdominal cavity on the ocular-side. This is the first record of S. longirostris in Korea, and we propose a new Korean name "Gin-ko-bo-seop-seo-dae" for this species.

• Journal of the Microelectronics and Packaging Society
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• v.31 no.3
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• pp.1-9
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• 2024

This paper addresses the significance of Cu/Polymer Hybrid Bonding technology in the advancement of semiconductor packaging. As the demands of the AI era increase, the semiconductor industry is exploring heterogeneous integration packaging technologies to achieve high I/O counts, low power consumption, efficient heat dissipation, multifunctionality, and miniaturization. The conventional Cu/SiO₂ Hybrid Bonding structure faces limitations such as achieving compatibility with CMP processes to attain surface roughness below 1nm and the occurrence of bonding defects due to particles. However, Cu/Polymer Hybrid Bonding technology, utilizing polymers, is gaining attention as a promising alternative to overcome these challenges. This study focuses on the deposition, patterning, and material properties of polymers essential for Cu/Polymer Hybrid Bonding, highlighting the advantages and potential applications of this technology compared to existing methods. Specifically, the use of polymers with low glass transition temperatures (Tg) is discussed for their benefits in low-temperature bonding processes and improved mechanical properties due to their high coefficients of thermal expansion. Furthermore, the study explores surface property modifications of polymers and the enhancement of bonding mechanisms through plasma treatment. This research emphasizes that Cu/Polymer Hybrid Bonding technology can serve as a critical breakthrough in developing high-performance, low-power semiconductor devices within the industry.

• Korean Journal of Environment and Ecology
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• v.28 no.1
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• pp.80-89
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• 2014

This study of the school's outdoor space for relaxing and activity of the two most numerous students, high heat and low heat with a green space, playground targets of thermal comfort indicators UTCI, PMV, WBGT using the thermal comfort students feeling compare the analyzed. The destination of this study, school facilities of Nam-gu, Namdong- gu, Incheon were studied and the investigation period was conducted from July to August. List of measurement, in the case of thermal comfort indicators, UTCI, PMV, WBGT was measured in the case of green, ratio of green coverage and GVZ was measured. GVZ analysis were as follows: A school ($4.71m^3/m^2$) B school ($3.34m^3/m^2$) C school ($0.38m^3/m^2$). Comparative analysis of the results of thermal comfort indicators by schools, UTCI was Green space $26.15{\sim}31.38^{\circ}C$ and playground $40.66{\sim}42.94^{\circ}C$, PMV values were 1.76 to 2.66 as a green space. WBGT was Green space $26.15{\sim}31.38^{\circ}C$, playground $31.67{\sim}34.53^{\circ}C$. Comparative analysis of the results of thermal comfort indicators UTCI, PMV, WBGT all A school, B school, C school, on the green space was comfortable levels more than playground. The results of the school type thermal comfort and green correlation analysis of thermal comfort UTCI, PMV, WBGT all solar radiation, globe temperature, and a positive correlation shown solar radiation, globe temperature is not comfortable, the higher was considered. UTCI, PMV, WBGT of thermal comfort indicator all ratio of green coverage, GVZ and negative correlation appears ratio of green coverage, GVZ was increased due to the lowering of the value of thermal comfort indicators was considered to be comfortable.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.3
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• pp.145-152
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• 2002

The composition of primary minerals in the rocks and secondary minerals of clay fractions of the soil developed on the cinder cones in the foot of Halla Mt., Jeju Island was investigated. The effects of parent materials on the physico-chemical properties and mineralogical characteristics were evaluated by XRD, DTA with the chemical composition of $H^+$ saturated clays. The main rock-forming minerals of a residual cinder cones were plagioclase with subsidiary minerals of hematite, gibbsite and quartz in the red cinder cone and of augite, quartz, feldspars and olivine in black cinder cone. It is demonstrated that ignition loss and sesquioxides content were higher in the red cinder soil than black cinder, which was resulted in the intermittent eruption of volcanic activity. For the chemical analysis of whole soils, $SiO_2/Al_2O_3$ ratio was increased from 2 to 3, but Ignition loss is decreased and $K_2O$ content are very low with increasing the soil depth in regard to the composition and kinds of clay minerals. No clay formation from micas mineral were in volcanic ashes. Dominant clay minerals of the cinder cone soils as a black and red cinder cone soil were allophane with some quartz and feldspars, while vermiculite, illite, kaolin were coexisted as a subsidiary minerals. But the red cinder cones soils had more hematite and gibbsite of the clay fractions than the black soils with magnetite. The exothermic pick of DTA at about $660^{\circ}C$ for cinder cone soils might be corresponded the oxidation magnetite to hematite reation. With regarding to the compositions of mineral detected by X-ray diffractogram and the properties of minerals by D.T.A thermogram, the dominant clay mineral was allophane of the cinder cone soils with some ferrous compounds, red colour of the cinder cone soils which are originated in hematite.

• Radiation Oncology Journal
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• v.26 no.3
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• pp.189-194
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• 2008

Purpose: We designed a water-based bolus device for radiation therapy in Kaposi's sarcoma. This study evaluated the usefulness of this new device and compared it with the currently used rice-based bolus. Materials and Methods: We fashioned a polystyrene box and cut a hole in order to insert patient's extremities while the patient was in the supine position. We used a vacuum-vinyl based polymer to reduce water leakage. Next, we eliminated air using a vacuum pump and a vacuum valve to reduce the air gap between the water and extremities in the vacuum-vinyl box. We performed CT scans to evaluate the density difference of the fabricated water-based bolus device when the device in which the rice-based bolus was placed directly, the rice-based bolus with polymer-vinyl packed rice, and the water were all put in. We analyzed the density change with the air gap volume using a planning system. In addition, we measured the homogeneity and dose in the low-extremities phantom, attached to six TLD, and wrapped film exposed in parallel-opposite fields with the LINAC under the same conditions as the set-up of the CT-simulator. Results: The density value of the rice-based bolus with the rice put in directly was 14% lower than that of the water-based bolus. Moreover, the value of the other experiments in the rice-based bolus with the polymer-vinyl packed rice showed an 18% reduction in density. The analysis of the EDR2 film revealed that the water-based bolus shows a more homogeneous dose plan, which was superior by $4{\sim}4.4%$ to the rice-base bolus. The mean TLD readings of the rice-based bolus, with the rice put directly into the polystyrene box had a 3.4% higher density value. Moreover, the density value in the case of the rice-based bolus with polymer-vinyl packed rice had a 4.3% higher reading compared to the water-based bolus. Conclusion: Our custom-made water-based bolus device increases the accuracy of the set-up by confirming the treatment field. It also improves the accuracy of the therapy owing to the reduction of the air gap using a vacuum pump and a vacuum valve. This set-up represents a promising alternative device for delivering a homogenous dose to the target volume.

• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.19-32
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• 2007

In Korea, there have been various methods of estimating groundwater recharge which generally can be subdivided into three types: baseflow separation method by means of groundwater recession curve, water budget analysis based on lumped conceptual model in watershed, and water table fluctuation method (WTF) by using the data from groundwater monitoring wells. However, groundwater recharge rate shows the spatial-temporal variability due to climatic condition, land use and hydrogeological heterogeneity, so these methods have various limits to deal with these characteristics. To overcome these limitations, we present a new method of estimating recharge based on water balance components from the SWAT-MODFLOW which is an integrated surface-ground water model. Groundwater levels in the interest area close to the stream have dynamics similar to stream flow, whereas levels further upslope respond to precipitation with a delay. As these behaviours are related to the physical process of recharge, it is needed to account for the time delay in aquifer recharge once the water exits the soil profile to represent these features. In SWAT, a single linear reservoir storage module with an exponential decay weighting function is used to compute the recharge from soil to aquifer on a given day. However, this module has some limitations expressing recharge variation when the delay time is too long and transient recharge trend does not match to the groundwater table time series, the multi-reservoir storage routing module which represents more realistic time delay through vadose zone is newly suggested in this study. In this module, the parameter related to the delay time should be optimized by checking the correlation between simulated recharge and observed groundwater levels. The final step of this procedure is to compare simulated groundwater table with observed one as well as to compare simulated watershed runoff with observed one. This method is applied to Mihocheon watershed in Korea for the purpose of testing the procedure of proper estimation of spatio-temporal groundwater recharge distribution. As the newly suggested method of estimating recharge has the advantages of effectiveness of watershed model as well as the accuracy of WTF method, the estimated daily recharge rate would be an advanced quantity reflecting the heterogeneity of hydrogeology, climatic condition, land use as well as physical behaviour of water in soil layers and aquifers.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.1
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• pp.11-19
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• 2013

Purpose: The aim of this study was to evaluate the heat generation in bone in vitro during the guided flapless drilling procedure and the effect of drilling methods on the heat generation. Materials and methods: A model that has missing the first and second mandibular molars bilaterally was used. In group A, classical flap implant surgery was performed. In group B, flapless implant surgery using surgical guide was performed. In group C, flapless implant surgery using surgical guide without up-and-down pumping motion was performed. Temperature was measured with k-type thermocouple and a real-time digital thermometer. The thermocouples were placed at 0.5 mm away from the osteotomy area at the depths of 3 mm and 6 mm. The measured values were evaluated with independent t-test. Results: The mean temperature generated was $27.2^{\circ}C$ ($SD{\pm}2.1^{\circ}C$) and $27.5^{\circ}C$ ($SD{\pm}2.3^{\circ}C$) for groups A and B, respectively. These differences were not statistically significant. In group C, the mean temperature was $37.0^{\circ}C$ ($SD{\pm}3.4^{\circ}C$). There were statistically significant differences between groups B and C with respect to the mean temperature. Conclusion: These findings suggest that guided flapless drilling with up-and-down pumping motion may not significantly increase the bone temperature.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.3
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• pp.46-53
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• 2009

Urbanization brings several changes to the natural environment. Its consequences can have a direct effect on climatic features, as in the Urban Heat Island Effect. One factor that directly affects the urban climate is the green area. In urban areas, vegetation is suppressed in order to accommodate manmade buildings and streets. In this paper we analyze the effect of green areas on the urban temperature in Seoul. The period selected for analysis was July 30th, 2007. The ground temperature was measured using Landsat TM satellite imagery. Land cover was calculated in terms of city area, water, bare soil, wet lands, grass lands, forest, and farmland. We extracted the surface temperature using the Linear Regression Model. Then, we did a regression analysis between air temperature at the Automatic Weather Station and surface temperature. Finally, we calculated the temperature decrease area and the population benefits from the green areas. Consequently, we determined that a green area with a radius of 500m will have a temperature reduction area of $67.33km^2$, in terms of urban area. This is 11.12% of Seoul's metropolitan area and 18.09% of the Seoul urban area. We can assume that about 1,892,000 people would be affected by this green area's temperature reduction. Also, we randomly chose 50 places to analysis a cross section of temperature reduction area. Temperature differences between the boundaries of green and urban areas are an average of $0.78^{\circ}C$. The highest temperature difference is $1.7^{\circ}C$, and the lowest temperature difference is $0.3^{\circ}C$. This study has demonstrated that we can understand how green areas truly affect air temperature.

• Journal of Korean Society of Forest Science
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• v.94 no.1 s.158
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• pp.34-38
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• 2005

This study, basic research for releasing new chestnut cultivar, is conducted to consider quantitative nut characteristics according to combinations and individuals In 11 chestnut hybrids. Number of bur on bearing branch(NBB) and nut yield(NY), which showed large difference among combinations, was superior in JO ($Joook{\times}Otanba$) and KO ($Kwangeun{\times}Otanba$) combinations, respectively. Average nut weight (NW) was 21.1g, the highest in EO ($Eunsan{\times}Otanba$) combination. Nut shape which was expressed to the rate of nut height and width, was investigated to the range of 1.13-1.23 in the all combinations, so nut shape of all combinations showed oval type. EO and JO combinations, which were measured to 30.0% and 27.5%, respectively in the percentage with the pericarp split(PPS), were produced more bad fruits than the others. OK ($Otanba{\times}Kwangeun$) combination, 1.7%, was the most excellent in the percentage of polyembryonic nuts(PPN), and the superior combinations which was measured to the below 5%, could be included five combinations. ER and RK combinations, were the highest values, 16.3% and $10.0kg/cm^2$, in soluble solids content(SSC) and kernel hardness (KH), respectively. NBB showed highly positive correlation with NY, but showed highly negative correlation with SSC and NW. NW showed highly positive correlation with PPS, but showed highly negative correlation with SSC and NH. PPS showed highly positive correlation with PPN. Eight individuals such as superior individuals could be selected by selection criteria.