• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.121-121
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• 2004

The groundwater in the Pocheon area occurs from both a fractured bedrock aquifer in igneous and metamorphic rocks and an alluvial aquifer with a thickness of <50 m, and forms a major source of domestic and agricultural water supply. In this study, we performed a hydrogeochemical study in order to identify the control of geochemical processes on groundwater quality. For this study, groundwater level and physicochemical parameters (EC, Eh, pH, alkalinity) were monitored once a month from a total of 150 groundwater wells between June 2003 to August 2004. A total of 153 water samples (13 surface water, 66 alluvial groundwater, 74 bedrock groundwater) were also collected and analyzed in February 2004. Groundwater chemistry in the study area is very complex, depending on a number of major factors such as geology, degree of chemical weathering, and quality of recharge water. Hydrochemical reactions such as the leaching of surficial and near-solace soil salts, dissolution of calcite, cation exchange, and weathering of silicate minerals are proposed to explain the chemistry of natural groundwater. Alluvial groundwaters locally have very high TDS concentrations, which are characterized by their chloride(nitrate)-sulfate-bicabonate facies and low Na/Cl ratio. Their grondwater levels are highly fluctuated according to rainfall event. We suggest that high nitrate content and salinity in such alluvial groundwaters originates from the local recharge of sewage effluents and/or fertilizers. Likewise, high concentrations of nitrate were also locally observed in some bedrock groundwaters, suggesting their effect of anthropogenic contamination. This is possibly due to the bypass flow taking place through macropores. Tile degree of the weathering of silicate minerals seems to be a major control of the distribution of major cations (sodium, calcium, magnesium, potassium) in bedrock groundwaters, which show a general increase with increasing depth of wells. Thermodynamic interpretation of groundwater chemistry shows that the groundwater in the study area is in chemical equilibrium with kaolinite and Na-montmorillonite, which indicates that weathering of plagioclase to those minerals is a major control of hydrochemistry of bedrock groundwater. The interpretation of the molar ratios among major ions, as well as the mass balance calculation, also indicates the role of both dissolution/precipitation of calcite and Ca-Na cationic exchange as bedrock groundwaters evolves progressively.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.3
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• pp.195-201
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• 1992

A Potential acid sulfate soil derived from continental Holocene deposits on the fan-base was found and it was characterized with improvement practices. Artesian wells were scattered in the area, and the imperfectly drained soils were featured by having fine loamy with 7~30% of gravels. The potential acid sulfate soil layers were typified by having darkness in color with around 3.3~3.8% of O.M. and 0.34~0.41% of total sulfur. Soil pH ranged from 3.4 to 3.8 but it was decreased to 1.9~2.5 after oxidation with $H_2O_2$. Ground water sprang out from an artesian well contained a high amount of minerals such as Na, Ca, Mg, K, etc. and about 80ppm of sulfate which seemed to be responsible for pyrite formation. The soil was classified to member of "Fine loamy, mixed, acid, mesic, sulfic Haplaquepts" in taxonomically, and "weak potential acid sulfate soils" in interpretatively. The installation of tile drains with adding fine earth and liming were effective. However, the pH goes down to 4.8 again after 3 years of improvement practices.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.6
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• pp.345-351
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• 2019

Recently, ink-jet printing technology has been applied for various industries such as semiconductor, display, ceramic tile decoration. Ink-jet printing has advantages of high resolution patterning, fast printing speed, high ink efficiency and many attempts have been made to apply functional materials with excellent physical and chemical properties for the ink-jet printing process. Due to these advantages, research scope of ink-jet printing is expanding from conventional two-dimensional printing to three-dimensional printing. In order to expand the application of ink-jet printing, it is necessary to optimize the rheological properties of the ink and the interaction with the substrate. In this study, photo curable ceramic complex ink containing nano silica particles were synthesized and its printability was characterized. Contact angle of the photo curable silica ink were modified by control of the ink composition and the surface property of the substrate. Effects of contact angle on printing resolution and three-dimensional printability were investigated in detail.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.7
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• pp.53-60
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• 2009

Motion estimation for H.264/AVC video CODEC is very complex and requires a huge amount of computational efforts because it uses multiple reference frames and variable block sizes. We propose the architecture of high-performance integer-pixel motion estimation circuit based on fast algorithms for multiple reference frame selection, block matching, block mode decision and motion vector estimation. We also propose the architecture of high-performance interpolation circuit for sub-pixel motion estimation. We described the RTL circuit in Verilog HDL and synthesized the gate-level circuit using 130nm standard cell library. The integer-pixel motion estimation circuit consists of 77,600 logic gates and four $32\times8\times32$-bit dual-port SRAM's. It has tile maximum operating frequency of 161MHz and can process up to 51 D1 (720$\times$480) color in go frames per second. The fractional motion estimation circuit consists of 22,478 logic gates. It has the maximum operating frequency of 200MHz and can process up to 69 1080HD (1,920$\times$1,088) color image frames per second.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.4
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• pp.41-49
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• 2008

H.264/AVC supports variable block motion compensation, multiple reference images, 1/4-pixel motion vector accuracy, and in-loop deblocking filter, compared with the existing compression technologies. While these coding technologies are major functions of compression rate improvement, they lead to high complexity at the same time. For the H.264 video coding technology to be actually applied on low-end / low-bit rates terminals more extensively, it is essential to improve tile coding speed. Currently the deblocking filter that can improve the moving picture's subjective image quality to a certain degree is used on low-end terminals to a limited extent due to computational complexity. In this paper, a performance improvement method of the deblocking filter that efficiently reduces the blocking artifacts occurred during the compression of low-bit rates digital motion pictures is suggested. In the method proposed in this paper, the image's spatial correlational characteristics are extracted by using the variable block information of motion compensation; the filtering is divided into 4 modes according to the characteristics, and adaptive filtering is executed in the divided regions. The proposed deblocking method reduces the blocking artifacts, prevents excessive blurring effects, and improves the performance about $30{\sim}40%$ compared with the existing method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.9
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• pp.896-905
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• 2004

In this paper, the design, fabrication and experiment on a planar array antenna with a flat-topped radiation pattern for a mobile base station antenna were described. The current distribution of an antenna aperture, which is easily realizable in a feeding network compared with the conventional one of sin(x)/x was optimized for shaping a desired flat-topped radiation pattern. The planar array antenna designed in this paper has a rectangular lattice and is composed of array elements of 16${\times}$8. Each radiating element, which is a microstrip element fed coaxially, has a linear vertical polarization and the feed network which use a Wilkinson power divider and a 180$^{\circ}$ ring hybrid coupler as a base element is designed. The flat-topped radiation pattern with 90$^{\circ}$ is shaped by 16 array elements with the element spacing of 0.55 λ$_{ο}$ in the azimuth plane, and the normal radiation pattern with 10$^{\circ}$ is shaped by 8 array elements with the element spacing of 0.65 λ$_{ο}$ in the elevation plane. Also, the planar array antenna is symmetrically divided into four parts. It consists of one hundred-twenty-eight radiating elements, thirty-two 1-4 column dividers, low 1-8 row dividers and one 1-4 input power divider. In order to verify electrical performances of the planar way antenna proposed in this paper, the experimental breadboard operated in tile band of 1.92～2.17 GHz(IMT2000 band) was fabricated, and its experimental results were a good agreement with simulation ones.

• Journal of the Economic Geographical Society of Korea
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• v.2 no.1_2
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• pp.145-167
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• 1999

The aim the this paper is to explore the processes of three Korean consumer electronics chaebols'entries into, and exits from tile EU in the context of European integration and enlargement and at the global, regional(EU), national and local level. Korean FDI in the EU has increased sharply since the late 1980s, while interacting with the processes of European integration and enlargement. In particular, the chaebols'FDI was caused by reactions against the intensification of Euro-trade regulations. As a result, these defensive entries have led such chaebols to create a strategy of ‘defensive Europeanisation’through the formation of forward and backward linkages between chaebols’affiliates and Korean suppliers within the EU. Nonetheless, defensive FDI has given rise to exits through active relocation within and outside the EU, since the ‘late 1980s’due in the main to (1) sensitive reactions against changing EU trade regulations and (2) failures to maintain cost-competitiveness in particular host regions. Along with these trends, chaebols’entries and exits are placed in contingent and paradoxical structures of the global -regional - national-local nexus, which has resulted from the mismatch of different EU policies such as trade, inward investment and regional policies.

• Journal of the Korean Home Economics Association
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• v.40 no.5
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• pp.25-37
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• 2002

The purpose of this study is to give basic information in comparison of workspace of traditional housing between traditional Waga and Choga in Jeju. The subjects of this study are six Waga (roofing tee system), authorized as Jeju Folklore Materials and five Choga (roofing thatch system), authorized as National Major Folklore Materials. The results of this study were as follows. 1. Household workspaces in Waga were separated by three places: Jungji, Chatbang, and Gopang. In Choga, it was separated by two places, Jungji and Gopang. 2 As a number of Jungji, Waga had one, which meant that two or more generations shared the kitchen facilities. Choga, it had one or two Jungji, which meant that each generation used different kitchen facilities. 3. functional space of division Waga was specific. So, meal preparation was done in Jungji, and dining was done in Chatpang. However, in Choga, both meal preparation and dining were done in Jungji. 4. The sequence of space, in the JungjiGeriBulDong style, which Jungji was located in the detached building, showed that the circulation directs: Gopang->Sangbang->Chatbang->Madang->Jungji. AnGeriJungji style, which Jungji was located in the main building, showed that the circulation directs: Gopang->Sangbang(->Chatbang)->Jungji. 5. In the size ratio of household workspace to whole size of the house, Waga occupied 30%, and Choga occupied 21%.

• The Korean Journal of Nuclear Medicine
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• v.19 no.2
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• pp.25-41
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• 1985

간흡충증은 한국 및 동남아세아에 널리 분포되어 있는 중요한 풍토병의 하나로서 진단은 전통적으로 분변검사에 의존하여 오고 있다. 최근 들어 담관내 간흡충 및 이의 합병증의 진단을 위해 ERCP 및 contrast cholangiogram등이 시도되었으나 실제에 이용하기에는 많은 제약이 있다 하겠다. 저자는 간흡충증에 있어서 최근 소개된 $^{99m}Tc-DISIDA$ hepatobiliary scintigraphy의 진단적 의의를 규명하고자 1982년부터 1983년까지 고신의대 부속 복음병원에서 검진한 간흡충증 환자 90명을 대상으로 하여 $^{99m}Tc-DISIDA$ hepatobiliary scintigraphy와 formalin-ether 원침법에 의한 분변검사를 시행하였다. $^{99m}Tc-DISIDA$ scintigram소견은 간내 담관 bile flow 및 총수담관 bile flow defect, 그리고 간세포기능의 정도에 따라 자료를 분석하였고 그외 합병증의 진단은 병록 기록, 수술 소견, ERCP 등에 의존하여 결론을 얻었다. $^{99m}Tc-DISIDA$ scintigraphy는 특이한 양상의 bile flow dynamics를 나타내었으며 간내 주담관의 intermittent irregular focal bile flow defect 및 tile flow stasis를 나타내고 말초담관의 bile flow defect는 경미하고 60분 내에 담관 bile flow activity의 완전한 배설을 나타내는 경우를 mild pattern, 간내 담관의 심한 irregular bile flow dynamics 및 간내담관의 심한 irregularity (담관내벽의 심한 불규칙성), 총수담관, 간내 주담관 및 말초 담관까지 심하게 irregular bile flow stasis를 나타내며 bile flow activity의 완전 베설이 $60\sim90$분사이 혹은 90분이상까지 인지된 경우를 moderate-severe pattern으로 분류하였다. 1) 분변검사상 간흡충증은 95검사중 70검사(환자 86명중 67명)에서 양성을 보여 분변 충난검사의 양성율은 73.7%였고 음성율은 26.3%였다. 2) $^{99m}Tc-DISIDA$ hepatobiliary scintigraphy는 90명중 70명에서 특이한 Cs-bile flow양성을 보였으며 양성율은 77.8%였으며 음성율은 22.2%였다. 3) $^{99m}Tc-DISIDA$ hepatobiliary scintigram양성율을 나타낸 환자 70명중 11명은 mild pattern, 59명은 moderate-severe pattern을 나타냈으며 그중 21명은 여러가지 간세포 기능 및 담관에 영향을 미치는 질환과 합병했지만 특이한 Cs-bile flow pattern을 dominent하게 나타내었으며 합병된 여러 질환들도 bile flow pattern상 인지 할 수 있었다. 4) $^{99m}Tc-DISIDA$ hepatobiliary scintigram 음성율을 나타낸 환자 20명중 8명은 만성간염, 5명은 간경변증, 3명은 재발성 농양성담관염(recurrent pyogenic cholangitis)과 간내담도의 stricture 및 담관담석증이 합병되었으며 scintigram상 합병증의 pattern을 나타냈고 4명에서는 low CBD obstruction을 나타내었으며 후에 CBD stone, CBD carcinoma, gall bladder Ca.의 porta hepatis 전이 및 clonorchis worms의 cluster에 의한 obstruction이 operation 및 ERCP로서 진단 되었다. 5) $^{99m}Tc-DISIDA$ hepatobiliary scintigraphy pattern은 현재의 자각증상과 관계된 dominent disease를 나타내었으며, 공간 점유병소도 multiple project images를 시행하므로서 쉽게 발견할 수 있었다. 이와 같이 간흡충증에 있어서 $^{99m}Tc-DISIDA$ hepatobiliary scintigram은 환자의 자각증상과 관계된 질환을 규명하는 데 필요한 정보를 얻었을 수 있었으며 간내담관의 damage정도를 규명하는데 필요한 procedure임이 판명되었다.

• Journal of the Korean Arthroscopy Society
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• v.7 no.2
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• pp.215-219
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• 2003

Purpose : To report the 'condylar cut-off sign', a new radiographic sign in knees with discoid lateral meniscus and to report the sensitivity, specificity, positive predictive value and negative predictive value of the sign to elucidate the diagnostic significance of the sign for discoid meniscus. Materials and Methods : Fifty knees with complete discoid lateral meniscus and fifty normal knees formed the basis of this study. All of them were arthroscopically confirmed fer the discoid or normal lateral meniscus. The authors developed a method to measure the length of the medial and lateral condylar were compare and analyzed. Results : Tile average ratio was 0.716 in the discoid meniscus group, and 0.902 in the normal group. The stastistical analysis by the T-test revealed the t-value -11.13(p<0.0001). Stastistical analysis by chi-square test using cut point 0.8, also showed significant difference between the two groups, with $76\%$ sensitivity, $100\%$ specificity, $100\%$ positive predictive predictive value and $81\%$ negative predictive value. The 'condylar cut-off sign' was readily detectable in all cases of discoid lateral meniscus, suggesting that the cut off sign could serve as a simple and reliable radiographic sign fur the diagnosis of discoid meniscus. Conclusion : The condylar cut-off sign on the Tunnel view of simple radiography of the knee can serve as a good sign for the diagnosis of discoid lateral meniscus, with $100\%$ positive predictive value.