• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.386-386
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• 2020

가뭄은 강수, 증발산, 대기온도, 토양수분 등 다양한 수문기상학적 인자들이 복합적으로 작용하여 발생되기 때문에 가뭄의 정확한 사상을 분석하는 것은 매우 어렵다. 또한 어떤 요인을 중심으로 고려하느냐에 따라 가뭄은 다양한 시각으로 정의되고 있다. 일정기간 평균 강수량보다 적은 강수로 인해 건조한 날이 지속되는 것, 즉 기상요소를 중심으로 가뭄을 정의하는 것을 기상학적 가뭄이라 하며, 작물의 생육에 필요한 수분을 중심으로 고려하는 것을 농업적 가뭄이라 한다. 또한 하천유량, 댐 저수량 등 전반적인 수자원 공급원의 부족을 수문학적 가뭄이라 한다. 이와 같이 다양하게 나타는 가뭄의 발생특성을 정량적으로 해석하기 위해 다양한 가뭄지수가 개발되어 왔다. 그러나 현재까지 개발된 가뭄지수들은 공통적으로 정형데이터를 활용하여 산정한다. 하지만 최근에는 비정형데이터를 활용하여 지수(Index)를 산정하거나, 재난관리에 적용하는 등 비정형 데이터의 활용이 급증하고 있다. 따라서 본 연구에서는 비정형 데이터(뉴스 데이터)를 활용하여 가뭄지수를 산정하고 기존의 가뭄지수들과의 상관성 분석을 실시 한 뒤, 지수결합을 통해 가뭄사상 분석의 새로운 방안을 제시하고자 하였다. 본 연구의 공간적범위는 2014~2015 충남서북부가뭄 지역 중 가장 큰 피해를 입었던 보령지역으로 선정하였으며 시간적범위는 2013~2016년으로 설정하였다. 비정형 데이터의 구축은 크롤링(Crawling)을 활용하여 네이버 뉴스의 기사를 수집하였으며 자료의 신뢰성을 위해 URL이 동일한 중복기사 및 '보령', '가뭄' 단어가 없는 기사는 제거하였다. 구축된 데이터를 기반으로 월별 빈도를 산출하고 표준점수(Z-score)로 환산하여 가뭄지수를 산정하였다. 산정된 가뭄지수가 어떤 가뭄의 유형(기상학적, 농업적, 수문학적)을 보이는지 확인하기 위해 기존의 가뭄지수들과 상관성분석을 실시하였으며, 가장 높은 상관성을 보이는 가뭄지수와 결합을 통해 새로운 가뭄 사상을 분석하였다. 본 연구에서 진행한 가뭄사상 분석은 향후 가뭄만이 아니라 다양한 재난분야에서 비정형 데이터를 활용한 분석의 기초로자료로 활용될 수 있을 것이다.

• The Korean Journal of Nuclear Medicine
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• v.35 no.1
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• pp.75-80
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• 2001

Purpose: There was little evidence that Tc-99m labeled ciprofloxacin (Infecton) located inside of bacteria. Antimicrobial activity of Infecton could be an indirect evidence of its location. We compared in vitro antimicrobial activities of Infecton and ciprofloxacin. Materials and methods: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Infecton and ciprofloxacin against three standard strains of bacteria, Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853 were measured using modified broth macrodilution techniques and pour plate methods, respectively. Data were expressed as mean${\pm}$SE (range). Results: MICs of Infecton and ciprofloxacin were $1.12{\pm}0.20\;(0.8{\sim}1.6){\mu}g/ml\;and\;0.35{\pm}0.04\;(0.2{\sim}0.4){\mu}g/ml$ for S. aureus, $0.03{\pm}0.005\;(0.025{\sim}0.05){\mu}g/ml\;and\;0.011{\pm}0.001\;(0.006{\sim}0.012){\mu}g/ml$ for E. coil, and $0.96{\pm}0.16\;(0.8{\sim}1.6){\mu}g/ml)\;and\;0.56{\pm}0.098\;(0.4{\sim}0.8){\mu}g/ml$ for P. aeruginosa, respectively. MBCs of Infecton and ciprofloxacin were $2.56{\pm}0.39\;(1.6{\sim}3.2){\mu}g/ml\;and\;0.88{\pm}0.2\;(0.4{\sim}1.6){\mu}g/ml$ for S. aureus, $0.04{\pm}0.05\;(0.025{\pm}0.05){\mu}g/ml\;and\;0.02{\pm}0.01\;(0.025{\sim}0.05)\;{\sim}g/ml$ for E coli, and $2.24{\pm}0.39\;(1.6{\sim}3.2){\mu}g/ml\;and\;1.44{\pm}0.16\;(0.8{\sim}1.6){\mu}g/ml$ for P. aeruginosa, respectively. Conclusion: Although both MICs and UBCs of Infecton were higher than those of ciprofloxacin, all three standard bacterial strains were sensitive to Infecton. It could be an indirect evidence that Tc-99m Infecton be a specific imaging agent for bacterial infection.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.2
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• pp.101-111
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• 2016

It is possible that aggregates add on to geopolymer based fly ash to mix mortar and concrete like cement. This is necessary to evaluate mineral composition, particle shape, surface, size distribution, density and absorption ratio for fine aggregates due to few detailed research to examine influence of fine aggregates properties on unhardened geopolymer concrete. In this research, used two different fine aggregates, Jumunjin sand(having quartz, mica, feldspar, pyroxene in mineral composition, more than 96% of total size between -0.60 and +0.30mm, angular shape and rough surface) and ISO sand(having almost all quartz in mineral composition, more than 51% size between -1.40 and +0.60mm, simultaneously varied size distribution, spherical shape and smooth surface). After an experimental result of the varied ratio of Si/Al=1.0-4.1 geopolymer paste, mix proportion respectively applied Si/Al=1.5 having the highest compressive strength to mortar and Si/Al=3.5 having the highest consistency to concrete. Geopolymer mortar by mixing with Jumunjin and ISO sand in varied range of 20-50wt.% showed flow size increase between 69.5 and 112.0mm, between 70.5 and 126.0mm respectively. Geopolymer concrete at an addition of 77wt.% of total aggregates ratio showed that average compressive strength was 32MPa and the consistency was favorable to molding. Since ISO sand observing varied size distribution, spherical shape, smooth surface, low absorption ratio resulted in advantageous properties on consistency of geopolymer, geopolymer concrete can be suitable for using the fine aggregates similar to ISO sand.

• Progress in Medical Physics
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• v.20 no.4
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• pp.308-316
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• 2009

To achieve the accurate evaluation of given absorbed dose from output dose of linear accelerator photon beam through investigate the characteristics of LiF:Mg,Cu,P TLD powder. This experimental TL phosphor is performed with a commercial LiF:Mg,Cu,P powder (Supplied by PTW) and TL reader (LTM, France). The TLD was exposed to 6 MV X rays of linear accelerator photon beam with range 15 to 800 cGy in blind dose at two hospitals. The dose evaluation of TLD was through the experimental algorithms which were dose dependency, dose rate dependency, fading and powder weight dependency. The glow curve has shown the three peaks which are 110, 183 and 232 degrees of heating temperature and the main dosimetric peak showed highest TL response at 232 high temperature. In this experiments, the LiF:Mg,Cu,P phosphor has shown the 2.5 eV of electron trap energy with a second order. This experiments guided the dose evaluation accuracy is within 1% +2.58% of discrepancy. The TLD powder of LiF:Mg,Cu,P was analyzed to dosimetric characterists of electron captured energy and order by glow shape, and dose-TL response curve guided the accuracy within 1.0+2.58% of output dose discrepancy.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.4 s.38
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• pp.11-18
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• 2006

In this paper, airborne LiDAR data were evaluated in horizontal and vertical accuracy. By using zigzag scanning type of LiDAR, GCPs are not tested directly. So points around GCPs were used in this evaluation. Building corner points were made from LiDAR's building planar and compared with ground surveyed GCPs, in horizontal accuracy test. Its accuracy shows 19cm average and 21cm RMSE and 15 points were within 20cm among 16 points. In vertical accuracy test, 41 GCPs were used and it shows 11cm average and 14cm RMSE and 75% of GCPs were within 15cm. This could be a criterion in topographic map modification and basic geographic DB and 3D data construction using airborne LiDAR data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.191-203
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• 1992

This paper dealt with the statistical values including mean, standard deviation, variance and coefficient of variation for 14 soil parameters available of Lade's double work-hardening model in order to predict the behaviour of granular soil. 27 sets of all 14 parameters for Baekma river sand were determined by regression using raw data acquired from 12 isotropic compression tests and 9 triaxial compression tests with the variation of confining pressure of 1, 2, and $4kg/cm^2$ respectively 3 times performed during this study. The characteristics of each parameters were investigated. By determining the range of the upper and lower bound dependent on the increase and decrease of the standard deviation from mean value of parameters, sensitivity of all the parameters was scrutinized, by which in turn the influence of experimental error generated inevitably during tests on the determination of soil parameters was also examined.

• The Journal of Engineering Geology
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• v.29 no.3
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• pp.211-222
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• 2019

This study evaluates the yield load and allowable bearing capacity of ground in compressive loading tests to confirm the effect of CPR foundation reinforcement. The average compressive strength of the injection materials was higher than the planned compressive strength. Standard penetration tests for each stratum showed that foundation reinforcement improved the average N values, thereby increasing the bearing capacity of the ground. Compressive loading tests on two CPR piles revealed that the total and net settlement due to the maximum load exceed that permissible for the CPR pile diameter. The yield load and allowable bearing capacity calculated by the settlement criterion and the load-settlement curves varied greatly with the method applied. Therefore, it seems to be necessary to determine the optimum value through comprehensive analysis after applying various yield load calculation methods.

• Information Systems Review
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• v.19 no.4
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• pp.111-134
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• 2017

This study compares the linkage effects and competitive advantage between ICT and automobile industry in Korea from 1996 to 2011 using input-output tables. The ICT industry is classified according to the International Standard Industry Classification. Results show that (1) the ICT industry exhibits linkage effects similar to those of automobile industry. (2) Both ICT and automobile manufacturing sectors exert significant effects on the demand and supply. Additionally, (3) ICT service and automobile sectors show linkage effects on demand and supply, respectively. The present results present the classification criteria of the ICT industry discussed to date and suggest economic effects and policy implications.

• Journal of the Korean earth science society
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• v.33 no.1
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• pp.32-38
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• 2012

Mean background concentrations of greenhouse gases such as $CO_2$ and $CH_4$ were estimated on Ulleungdo using PICARRO Cavity Ring-Down Spectroscopy (CRDS) analyzer. To improve the accuracy of $CO_2$ and $CH_4$ concentrations, a standardized QA${\cdot}$QC (Quality Assurance Quality Control) procedure was employed with three steps: 1) the inspection procedure of physical limitation (e.g. the exclusion of data corresponding to the number of data of ${\leq}$50%) for hourly mean values, 2) a stage inspection (e.g. the use of data corresponding to ${\geq}15$ observations per day) for daily mean values, and 3) a fast fourier transform (FFT) analysis using curve-fitting methods for the investigation of climatic characteristics. The monthly mean concentrations of $CO_2$ and $CH_4$ derived from three-step QA${\cdot}$QC procedure were then compared with those observed at Anmyundo (Korea) and Ryori (Japan). Overall, the error of mean $CO_2$ and $CH_4$ concentrations estimated in this study distinctly decreased. However, in comparison with their concentrations monitored at Ryori, the $CO_2$ concentration at estimated at Ulleungdo is soemwhat lower than that of Anmyundo due to the missing data, which is statistically significant. On the other hand, the former has a statistically significant higher value of $CH_4$ that of the latter.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.5
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• pp.502-511
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• 1994

Investigated were the relationships between plumule elongation characteristics and seedling emergence of 98 varieties including native, improved and red rice varieties of Korea, and varieties from U.S.A., Italy, Japan, etc. under proper and excess soil moisture regimes. Under excess soil moisture condition the seedling emergence and establishment rates were much lower in most of the varieties and the seedling emergence rates were delayed substantially in all varieties employed. The seedling emergence rates were lowest in dwarf and some semi-dwarf varieties showing poor plumule elongation under proper soil moisture condition. The seedling emergence and establishment rates were significantly correlated with the length of mesocotyl, coleoptile and incomplete leaf under both soil moisture regimes, and with the lower first and second internode length under excess soil moisture condition. Average emergence duration showed significant negative correlation with the length of mesocotyl, coleoptile and incomplete leaf under both soil moisture regimes and significant positive correlations with the first and third lower internode length. Based on the standardized partial regression analysis only the variations of mesocotyl and coleoptile length contributed significantly to the varietal difference in seedling establishment rate, and so did the variations of mesocotyl and incomplete leaf length to the varietal differences in emergence speed. In conclusion varieties with greater elongation characteristics of mesocotyl, coleoptile and incomplete leaf are desirable for higher and speedy seedling establishment in dry-direct seeding.