• 한국안전학회지
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• 제31권5호
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• pp.102-108
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• 2016

This paper presents a new strength method of underground box structures under additional surface load. An L-bracing using pre-flexed steel member threads called the "Pre-flex strength method" is used to improve capacity of the RC box structure under earth pressure due to additional surface load. The pre-flexed steel member is fixed the top and bottom of the structure after chemical anchor was installed by drilling hole on the box structure. The structural performance was evaluated analytically. 3 types of underground RC box structure were used; $2.0m{\times}2.0m$, $3.0m{\times}3.0m$ and $4.0m{\times}4.0m$. For the performance evaluation, structure analysis were performed on moment and shear resisting structures with and without pre-flex strength method. Numerical results confirmed that the proposed strength member system installed on underground RC box structures enhanced the strength capacity. The feasible region of the proposed pre-flex strength method in accordance with the earth pressure due to additional surface depth was evaluated.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.123-131
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• 2009

본 연구에서는 2차원 및 3차원 유한요소 해석을 이용하여 심층혼합처리 공법에 의한 연약지반 개량시 개량 심도를 결정 하였고, 그 결과는 다음과 같았다. 1. 2차원 해석 결과는 3차원 해석 결과 보다 약 10% 정도 크게 해석되었다. 2. 연약지반의 치환율이 5%이하 일 때 침하량은 급격히 증가하였다. 3. 심층혼합공법으로 연약지반 개량시 횡방향 간격 3m, 종방향 간격 6m, 그리고 8m의 심도로 개량하는것이 가장 경제적인 것으로 나타났다. 4. 심층혼합공법으로 연약지반 개량시 2차원 유한요소 해석보다 3차원 유한요소 해석으로 결정되어야 한다.

• 한국식품조리과학회지
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• 제26권3호
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• pp.246-251
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• 2010

This study was conducted to investigate the quality characteristics of guavapyun after the addition of different ratios of extract (0.25, 0.5, 0.75, 1.0%), non-extract and vitamin C. The quality if the pyun containing 0.5% of the guava fruit extract (guavapyun) and vitamin C was higher compared with the quality of the control pyun. In the results of the proximatecomposition, the content of water was high in the control pyun relative to the vitamin C pyun and guavapyun and the carbohydrate, ash, crude lipid and protein content was high in guavapyun. The sweetness, pH and color (L, a, b value) were very high in the samples. The texture, hardness, chewiness and gumminess were significantly high in the control pyun and the adhesiveness and cohesiveness were high in guavapyun. However, there were no significant differences in springiness between the control and the added samples. The total phenolic content was higher in guavapyun (23.57 mg GAE/100 g) than the control pyun (18 mg GAE/100 g) and vitamin C pyun(15.05 mg GAE/100 g). The antioxidant activities determined by the DPPH method and ABTS method was higher in guavapyun (41.37 mM TE/g, 15.35 mM TE/g) than the control pyun (4.43 mM TE/g, 2.17mM TE/g) and vitamin C pyun (11.33 mM TE/g, 4.51 mM TE/g). Using the FRAP method, guavapyun(9.06 mM TE/g) was shown to exhibit a stronger ferrous ion chelating activity than the control pyun (4.49mM TE/g) and vitamin C pyun (7.03 mM TE/g). Thus, the studied indigenous guavapyun was high in both antioxidative activity and total phenolic content.

• 대한원격탐사학회지
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• 제24권5호
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• pp.483-496
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• 2008

Qualified ground control points (GCPs) are required to construct a digital elevation model (DEM) from a pushbroom stereo pair. An inverse geolocation algorithm for extracting GCPs from ERS SAR data and the SRTM DEM was recently developed. However, not all GCPs established by this method are accurate enough for direct application to the geometric correction of pushbroom images such as SPOT, IRS, etc, and thus a method for selecting and removing inaccurate points from the sets of GCPs is needed. In this study, we propose a method for evaluating GCP accuracy and winnowing sets of GCPs through orientation modeling of pushbroom image and validate performance of this method using SPOT stereo pair of Daejon City. It has been found that the statistical distribution of GCP positional errors is approximately Gaussian without bias, and that the residual errors estimated by orientation modeling have a linear relationship with the positional errors. Inaccurate GCPs have large positional errors and can be iteratively eliminated by thresholding the residual errors. Forty-one GCPs were initially extracted for the test, with mean the positional error values of 25.6m, 2.5m and -6.1m in the X-, Y- and Z-directions, respectively, and standard deviations of 62.4m, 37.6m and 15.0m. Twenty-one GCPs were eliminated by the proposed method, resulting in the standard deviations of the positional errors of the 20 final GCPs being reduced to 13.9m, 8.5m and 7.5m in the X-, Y- and Z-directions, respectively. Orientation modeling of the SPOT stereo pair was performed using the 20 GCPs, and the model was checked against 15 map-based points. The root mean square errors (RMSEs) of the model were 10.4m, 7.1m and 12.1m in X-, Y- and Z-directions, respectively. A SPOT DEM with a 20m ground resolution was successfully constructed using a automatic matching procedure.

• 한국가축번식학회지
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• 제21권2호
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• pp.95-102
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• 1997

The studies on the carried out to investigate the effective concentration of cryoprotectant agents and sucrose by one-step straw method of bovine embryos. The follicular oocytes were cultured in TCM-199 medium containing 10 IU/ml PMSG(Sigma, USA), 10 IU/ml hCG(Sigma, USA), 1$\mu\textrm{g}$/ml $\beta$-estradiol(Sigma, USA) and 10% FCS for 24~48 hrs in incubator with 5% CO2 in air at 38.5$^{\circ}C$ and then matured oocytes were again cultured for 12~18 hrs with motile capacitated sperm by preincubation of heparin. The bovine embryos following dehydration by cryoprotective agents and various concentrations of sucrose were directly plunged into liquid nitrogen and thawed in 3$0^{\circ}C$ water. Survival and in vitro developmental rate was defined as devellpmental rate on in vitro culture or FDA-test. The results are smmarized as followes : 1. The high in vitro developmental rates of bovine frozen embryos after rapidly thawed in freezing medium was attained 2.0M glycerol, 2.0M DMSO, 1M or 2.0M propanediol. 2. The high in vitro developmental rates of bovine frozen embryos after rapidly thawed in freezing medium was obtained single cryoprotectant(6.7~17.4%) than mixed cryoprotectants(6.7~16.7%). 3. In vitro developmental rate of bovine embryos after rapid frozen-thawing in the freezing medium added 0.25M and 0.50M sucrose were higher cleavage rate than those of sucrose concentration of 0.75M and 1.00M. 4. The freezing methods on in vitro developemental rates of bovine embryos was attained slow freezing method(9.70~15.6%) higher than rapid freezing method(9.4~13.3%).

• 한국습지학회지
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• 제21권4호
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• pp.298-304
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• 2019

이 논문에서는 한국의 가로수에 대한 바람 취약성을 유도하는 분석 방법을 보여준다. 몬테 카를로 시뮬레이션 방법은 도시 가로수의 파괴 확률을 결정하는 데 사용되었다. 이 확률 결과는 대구 지역의 가로수를 기반으로 4 가지 유형에 대한 바람 취약성 매개 변수를 결정하는 데 사용되었으며, 이로 인해 풍하중에서 가로수 손상 확률에 영향을 미치는 주요 요인이 직경이라는 것을 나타낸다. 또한, 선택된 4 가지 유형 중에서 높이 7m, 직경 35cm의 가로수는 손상률이 제일 낮은 반면, 높이 8m, 직경 30cm의 가로수는 가장 낮은 풍하중에서 저항하였다. 높이 7m의 가로수의 평균 손상 풍속은 직경 30cm 및 35cm에 대해 각각 43.8m/s 및 50.6m/s로 나타났으며, 높이 8m의 가로수의 평균 손상 풍속은 직경 30cm 및 35cm에 대하여 각각 38.7m/s 및 45.4m/s로 나타났다.

• 호남수학학술지
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• 제30권2호
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• pp.399-409
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• 2008

We consider the most generalized quadratic matrix equation, Q(X) = $A_7XA_6XA_5+A_4XA_3+A_2XA_1+A_0=0$, where X is m ${\times}$ n, $A_7$, $A_4$ and $A_2$ are p ${\times}$ m, $A_6$ is n ${\times}$ m, $A_5$, $A_3$ and $A_l$ are n ${\times}$ q and $A_0$ is p ${\times}$ q matrices with complex elements. The convergence of Newton's method for solving some different types of quadratic matrix equations are considered and we show that the elementwise minimal positive solvents can be found by Newton's method with the zero starting matrices. We finally give numerical results.

• 한국대기환경학회지
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• 제18권2호
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• pp.161-170
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• 2002

Total(=wet+dry) atmospheric depositions were collected by filtration-sampling method at 17 sampling sites of the coal-fired power plant area from September 1999 to January 2000. The soluble and insoluble fractions of deposition were also measured to investigate a suitability of simplified collection method for a long-term monitoring of total deposition. In the study, the 50% of sampled soluble fractions showed the electric conductivity (E.C.) of below 50 $\mu$S/cm and the 42% of them showed the lower pH than 5.0. The monthly mean fluxes of water soluble ionic components; S $O_4$$^{2-}$, C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , N $a^{+}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$ were 168.4 kg/k $m^2$.month, 100.5 kg/k $m^2$.month, 88.6kg/k $m^2$.month, 31.3kg/k $m^2$.month, 25.6 kg/k $m^2$.month, 13.3 kg/k $m^2$.month, 8.7 kg/k $m^2$.month, 43.1kg/k $m^2$.month, respectively. The mean ionic concentration of all sample(n=79) was 314 $\mu$eq/ι, with contributions of 24.2% and 23.0% by [nss-C $a^{2+}$] and [nss-S $O_4$$^{2-}$]. The ratio of [N $O_3$$^{[-10]}$ ]/[nss-S $O_4$$^{2-}$] and [N $H_4$-C $a^{2+}$] were found to be 0.52 and 0.68, respectively.espectively.

• 한국광학회지
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• 제16권4호
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• pp.340-344
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• 2005

화염가수분해 증착법(FHD : Flame Hydrolysis Deposition)으로 제작된 Ge이 첨가된 BPSG(Boro-Phospho-Silicate-Glass)막의 표면을 절단톱(dicing saw)을 이용하여 일정한 깊이로 절단함으로써 각 단위 마이크로렌즈 셀들을 형성시켰다. 또한 절단된 각 단위 마이크로렌즈 셀들을 가열용융(thermal reflow) 방법을 이용하여 $1200^{\circ}C$에서 가열용응시킴으로써 직경이 $53.4{\mu}m$인 마이크로렌즈 어레이를 제작할수 있었다. 이 때 렌즈간 간격은 $70{\mu}m,$ 렌즈 두께는 약 $28.4{\mu}m$이었다. 제작된 마이크로렌즈 어레이의 형상을 이미지-프로세스로 분석하였으며. 초점거리는 $62.2{\mu}m$이었다. 본 제작방법은 일반적인 사진식각 공정을 이용한 마이크로렌즈 제작보다 간단하면서도 저렴한 비용으로 제작이 가능하다. 또한 곡률반경의 조절이 용이하고, 보다 정밀하며 다양한 마이크로렌즈 어레이를 구현할 수 있다.

• Journal of Animal Science and Technology
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• 제55권5호
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• pp.417-425
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• 2013

동결 닭 PGCs의 생식계열 키메라를 이용한 생체에의 복원을 실용화 하기 위해서는, 닭 PGCs의 동결보존기술의 향상에 의해 동결 및 융해 후의 많은 생존세포를 확보 하는 것과, 생식계열 키메라의 제작효율을 높이는 것이 반드시 필요하다. 닭 PGCs는 배양 5.5일령의 닭 원시생식선으로부터 채취하고, ACS 방법에 의해서 순수 닭 PGCs를 분리했다. 닭 PGCs의 동결보존실험결과 다음의 4종류의 동결방법을 각각 비교 검토했다. 1. 플라스틱 스트로에 의한 완만동결법 (SF), 동결보호물질은 2M 에틸렌 글리콜 (EG), 2. 스트로에 의한 급속동결법 (RF), 8M EG + 7% PVP, 3. 동결용 Cryotube에 의한 SF, 2M EG, 4. 튜브에 의한 SF, 10% DMSO. 동결 및 융해 후의 PGCs의 생존율은 각각 76.4%, 70.6%, 80.5%, 78.1%로 관찰되었다.