• Korean Journal of Microbiology
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• v.49 no.2
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• pp.156-164
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• 2013

Actinomycetes produce diverse secondary metabolites which have the primary importance in medicine, agriculture and food production, and key to this is their ability to interact with other organisms in natural habitats. In this study, we have investigated the taxonomical and functional diversity of actinomycetes in fecal sample of rhinoceros beetle larvae (Allomyrina dichotoma L.) by using culture-dependent and -independent approaches. For the culture-independent approach, the community DNA was extracted from the sample and 16S rRNA genes of actinomycetes were amplified using actinomycetes-specific PCR primers. Thirty-seven clones were classified into 15 genera and 24 species of actinomycetes. For the culture-dependent approach, 53 strains were isolated from larval feces, of which 27 isolates were selected based on morphological characteristics. The isolates were classified into 4 genera and 14 species, and 24 isolates (89%) were identified as the genus Streptomyces. Many of the representative isolates had antimicrobial activities against plant pathogenic fungi and Gram-positive bacteria. In addition, most of the isolates (78%) showed biochemical properties to hydrolyze cellulose and casein. The results demonstrated that diverse and valuable actinomycetes could be isolated from insect fecal samples, indicating that insect guts can be rich sources for novel bioactive compounds.

• Communications of Mathematical Education
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• v.28 no.1
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• pp.155-178
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• 2014

This study starts from the problem that although the solution premise the generality in algebra, a lot of students don't understand the generality of algebraic solution. We investigated this problem to understand cognitive characteristic of students. Moreover, we tried to find the elements which helping students understand the generality of algebraic solution. The purpose is to get the didactical implications. To do this, we had investigated the cognition of twenty middle school students for generality of solution. As result, 70 % of them didn't cognize the generality of solution. We had a personal interview with four students who showed a lack of sense of generality of algebraic solution. Putting into three action which we designed to help the change of their recognition, we observed and analyzed students cognizance change. Three action is the check of accordance for individual results, the check of solution accordance for different variables and the check of arbitrary variables. Based on the analysis, we discussed on the cognitive characteristic of students and the effect of three action. We finally discussed on the didactical implications to help students understand the generality of algebraic solution.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.3
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• pp.125-140
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• 2017

Until recently, regression based spatial interpolation methods and Kriging based spatial interpolation methods have been largely used to estimate land price or housing price, but less attention has been paid on comparing the performance of these spatial interpolation methods. In this regard, this research applied regression based spatial interpolators and Kriging based spatial interpolators for estimating the land prices in Dalseo-gu, Daegu metropolitan city and evaluated the accuracy of eight spatial interpolators. OLS, SLM, SEM, and GWR were used as regression based spatial interpolators while SK, OK, UK, and CK were employed as Kriging based spatial interpolators. The global accuracy was statistically evaluated by RMSE, adjusted RMSE, and COD. The relative accuracy was visually compared by three-dimensional residual error map and scatterplot. Results from statistical and visual analyses indicate that GWR reflecting the spatial non-stationarity was a relatively more accurate spatial predictor to estimate land prices in the study area than SAR and Kriging based spatial interpolators considering the spatial dependence. The findings from this research will contribute to the secondary research into analyzing the urban spatial structure with land prices.

• Journal of Wetlands Research
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• v.17 no.1
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• pp.91-100
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• 2015

The aim of this study is to compare and analyze plant monitoring results of 2012 and 2013 for three artificial wetlands of Binae, Sedo, and Okpo areas in Namhan river, Keum river, and Nakdong river respectively. As the results, the Binae wetland in 2013 shows the same environment with 2012, that is, Willow and Common reed were dominant and the distributed plants in the wetland were Phragmites japonica Steud, Carex dispalta Boott, and Humulus japonicus in lowland of river side. Especially, Humulus japonicus was increased in summer season and Willow was increased in lowland of 초원. In Okpo wetland, Water chestnut was appeared in 2013 which it was not in 2012. Reed distribution was reduced in 2013 comparing to 2012 but Pussy willow distribution was not changed in 2013. In Sedo wetland, Secondary grassland was artificially planted in 2013 and so the colony was changed to Chinese Lespedeza and also most of plant colony was changed to Colt's-tail. Therefore, we can know that wetted transition rather than dried transition will be occurred in the Binae wetland. However, the Okpo wetland has monotonic change and so the transition will be proceeded with long time. The Sedo wetland showed wetted and dried transitions exist together. Therefore, the wetland will be changed to Reeds, Common reed, and Willow colonies.

• Tuberculosis and Respiratory Diseases
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• v.64 no.2
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• pp.95-101
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• 2008

Background: Drug resistant tuberculosis (TB) in patients who have not received previous TB treatment (initial drug resistance) is a serious problem for the control of TB. However, prevalence of initial drug resistance among pulmonary TB patients has not been well characterized in Korea, especially in the private sector. We assessed the prevalence of initial drug resistance and evaluated the risk factors for drug resistance in pulmonary TB patients, at a regional tertiary hospital in Cheonan. Methods: We performed a drug susceptibility test for both first and second line anti-TB drugs in all culture-confirmed pulmonary TB patients who had not received a previous TB treatment at Dankook University Hospital from September 2005 to September 2007. In addition, we evaluated the initial drug resistance pattern and clinical characteristics of patients to evaluate the risk factors for initial drug resistance. We also assessed the influence of the drug susceptibility test results on the treatment regimen. Results: Of the total 156 cases where the drug susceptibility test was performed, resistance to at least one anti-TB drug was found in 21 cases (15.6%) and multidrug resistance, where TB was resistant to at least isoniazid and rifampin, was found in one case (0.6%). Multivariate logistic regression showed no clinical characteristics were independently associated with initial drug resistance. Of the total 156 patients who underwent the drug susceptibility test, the treatment regimen was changed for 15 patients (9.6%) according to the results of the drug susceptibility test. Conclusion: Initial drug resistance is common and the drug susceptibility test is informative for pulmonary TB patients who have not received previous TB treatment.

• Korean Journal of Environmental Agriculture
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• v.32 no.1
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• pp.48-54
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• 2013

BACKGROUND: Sorghum (Sorghum bicolor (L.) Moench) ranks as the 6th most planted crop in the world behind wheat, rice, maize, soybean, and barley. The objective of this study was to identify bio-marker among sorghum cultivars using proteomics approach such as two-dimensional polyacrylamide gel electrophoresis (2-DE) coupled with mass spectrometry (MS). METHODS AND RESULTS: Proteins were extracted from sorghum seed, and separated by 2-DE. Total 652 spots were detected from 4 different sorghum seed after staining of 2-DE with colloidal Coomassie brilliant blue (CBB). Among them, 8 spots were differentially expressed and were identified using MALDI-TOF/TOF mass spectrometry. They were involved in RNA metabolism (spot1, spot 4), heat shock proteins (HSPs, spot 2), storage proteins (spot 3, spot 5, and spot 6), and redox related proteins (spot 8). Eight of these proteins were highly up-regulated in Whinchalsusu (WCS). The HSPs, Cupin family protein, and Globulin were specifically accumulated in WCS. The DEAD-box helicase was expressed in 3 cultivars except for WCS. Ribonuclease T2 and aldo-keto reductase were only expressed in 3 cultivars except for Daepung-susu (DPS). CONCLUSION(S): Functions of identified proteins were mainly involved in RNA metabolism, heat shock protein (HSP), and redox related protein. Thus, they may provide new insight into a better understanding of the charactreization between the cultivars of sorghum.

• Economic and Environmental Geology
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• v.40 no.4
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• pp.473-490
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• 2007

Strata of the Kachi-1 well, Kunsan Basin, offshore western Korea, were analyzed by using integrated stratigraphy approach. As a result, five distinct unconformity-bounded units are recognized in the well: Triassic, Late Jurassic-Early Cretaceous, Early Cretaceous, Late Cretaceous, and Middle Miocene units. Each unit represents a tectono-stratigraphic unit that provides time-sliced information on basin-forming tectonics, sedimentation, and basin-modifying tectonics of the Kunsan Basin. In the late Late Jurassic, development of second- or third-order wrench faults along the Tan-Lu fault system probably initiated a series of small-scale strike-slip extensional basins. Continued sinistral movement of these wrench faults until the Late Cretaceous caused a mega-shear in the basin, forming a large-scale pull-apart basin. However, in the Early Tertiary, the Indian Plate began to collide with the Eurasian Plate, forming a mega-suture zone. This orogenic event, namely the Himalayan Orogeny, continued by late Eocene and was probably responsible for initiation of right-lateral motion of the Tan-Lu fault system. The right-lateral strike-slip movement of the Tan-Lu fault caused the tectonic inversion of the Kunsan Basin. Thus, the late Eocene to Oligocene was the main period of severe tectonic modification of the basin. After the Oligocene, the Kunsan Basin has maintained thermal subsidence up to the present with short periods of marine transgressions extending into the land part of the present basin.

• The Korean Journal of Applied Statistics
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• v.20 no.2
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• pp.267-280
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• 2007

Various single-valued design optimality criteria such as D-, G-, and V-optimality are used often in constructing optimal experimental designs for mixture experiments in a constrained region R where lower and upper bound constraints are imposed on the ingredients proportions. Even though they are optimal in the strict sense of particular optimality criterion used, it is known that their performance is unsatisfactory with respect to the prediction capability over a constrained region. (Vining et at., 1993; Khuri et at., 1999) We assume the quadratic polynomial model as the mixture response surface model and are interested in finding efficient designs in the constrained design space for a mixture. In this paper, we make an expanded list of candidate design points by adding interior points to the extreme vertices, edge midpoints, constrained face centroids and the overall centroid. Then, we want to propose a robust design with respect to D-optimality, G-optimality, V-optimality and distance-based U-optimality. Comparing scaled prediction variance quantile plots (SPVQP) of robust designs with that of recommended designs in Khuri et al. (1999) and Vining et al. (1993) in the well-known examples of a four-component fertilizer experiment as well as McLean and Anderson's Railroad Flare Experiment, robust designs turned out to be superior to those recommended designs.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.94-94
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• 2003

최근, 새로운 전자재료로서 GaN 분말의 합성과 응용에 관한 연구가 많이 이루어지고 있다. CaN 분말은 열처리 과정 중 분해를 방지하기 위한 표면 보호용 소재, CaN 박막 또는 벌크 결정을 성장하기 위한 precursor 및 대면적 평판표시소자 제작을 위한 전기발광소자용 소재 등에 적용되고 있다. 일반적으로 100$0^{\circ}C$ 이상의 온도에서Ga과 NH$_3$를 반응시키거나, Ga이 포함된 화합물반도체 또는 산화물 및 질산염 등을 NH$_3$ 분위기에서 가열시켜 GaN 분말을 합성시키고 있다. 본 논문에서는 출발물질로서 GaOOH를 채택하고, 이를 NH$_3$ 가스를 흘리면서 가열 반응시켜 GaN 분말을 합성하고 X선 회절분석 방법을 사용하여 GaN의 합성에 대한 반응기구를 조사하였다. GaN 분말을 합성하기 위하여 GaOOH 분말 1g을 석영 용기에 담아 석영 반응관 내에 위치시키고, 반응관 내부를 $10^{-3}$ torr의 진공으로 배기한 후 $N_2$를 주입하면서 전기로의 온도를 1$0^{\circ}C$/min으로 승온시켰다. 반응온도는 300~l17$0^{\circ}C$의 범위에서 변화시켰고, 반응시간은 10분부터 24시간까지 변화시켰으며, NH$_3$의 유량은 300~700 sccm의 범위에서 변화시켰다. GaN의 반응역학을 조사하기 위하여 X선 회절도에서 특정 성분의 회절강도는 시료 내에 포함된 특정 성분의 량에 직접 비례한다고 가정하고, 2$\theta$=37$^{\circ}$부근에서 관찰되는 GaN의 (101)면에 의한 회절강도를 측정하고, 이를 GaN의 생성량으로 고려하였다.}C$로 소결 하였다. coating 결과 박리현상은 없었으나, 표면과 단면의 SEM분석결과 다소 porous한 박막층이 형성되었으며, Ca이온이 지지체로 permeation되는 현상이 발생하였다. 이와 같은 결과로부터 보다 치밀한 박막생성을 위해, slurry 제조조건을 변화시켰으며, Ca이온의 migration을 막기 위해 barrier layer를 이용하였다 완전 소결된 지지체는 가스투과도와 전기전도도측정을 통하여 특성을 평가하였다.였다.다.m이하의 NH$_3$ 가스를 검출할 수 있었다.기 화강암 관입 이전에 좌수향 전단 운동에 의해 부분적으로 재활성 되었으며, 후기 화강암의 관입 이후에 재차 우수향 전단운동으로 활성화 되었음을 알 수 있다. 이상의 결과를 종합하면 호남전단대는 쥬라기 중기에 발생한 광역적인 우수향의 연성전단운동이나, 운동 특성은 연속적이기 보다는 단속적으로 일어난 것으로 생각된다.리 폐 관류는 정맥주입 방법에 비해 고농도의 cisplatin 투여로 인한 다른 장기에서의 농도 증가 없이 폐 조직에 약 50배 정도의 고농도 cisplatin을 투여할 수 있었으며, 또한 분리 폐 관류 시 cisplatin에 의한 직접적 폐 독성은 발견되지 않았다이 낮았으나 통계학적 의의는 없었다[10.0%(4/40) : 8.2%(20/244), p>0.05]. 결론: 비디오흉강경술에서 재발을 낮추기 위해 수술시 폐야 전체를 관찰하여 존재하는 폐기포를 놓치지 않는 것이 중요하며, 폐기포를 확인하지 못한 경우와 이차성 자연기흉에 대해서는 흉막유착술에 더 세심한 주의가 필요하다는 것을 확인하였다. 비디오흉강경수술은 통증이 적고, 입원기간이 짧고, 사회로의 복귀가 빠르며, 고위험군에 적용할 수 있고, 무엇보다도 미용상의 이점이 크다는 면에서 자연기흉에 대해 유용한 치료방법임에는 틀림이 없으나 개흉술에 비

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.208-208
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• 2003

RF 마그네트론 스퍼터링법을 이용하여 Ar과 $O_2$의 유량을 25sccm씩 흘리면서 $SiO_2$/Si기판 위에 Sn $O_2$ 박막을 증착하였다. 증착된 박막은 columnar 구조로 성장하였으며 많은 입자들이 뭉쳐서 형성된 양배추꽃(cauliflower) 형태의 뭉친 입자(agglomerates)를 가지는 표면형상이 관찰되었다. 분위기에 따른 어닐링 효과를 확인하기 위하여 50$0^{\circ}C$에서 공기와 질소 분위기하에서 열처리하였다. 열처리한 후 표면거칠기가 개선되었으며, 표면형상의 변화가 발생하였다. 특히 50$0^{\circ}C$, 질소분위기에서 어닐링한 경우는 양배추꽃 형태의 표면형상이 소수의 작은 입자가 뭉친 형태로 분리되면서 입도분포가 개선되었다. 이러한 결과는 어닐링 과정에서 발생되는 응력을 완화시키기 위하여 표면형상의 변화가 발생하는 것으로 판단된다. XPS 측정 결과, 질소 분위기에서 어닐링한 후에 OIs와 Sn5/3d 피크가 낮은 결합에너지에 위치하고 있어 산소공공의 농도가 어닐링 전에 비하여 증가하였음을 확인할 수 있다. 어닐링 전후에 Sn $O_2$ 박막의 면저항 측정 값은 XPS 결과와는 달리 질소 분위기 어닐링한 후에 오히려 면저항값이 크게 증가하였다. 이러한 결과는 질소 분위기 어닐링한 후 표면형상의 변화에 기인하여 입자간의 연결성이 저하되어 면저항값이 증가한 것으로 추정된다. 산소분위기에서 어닐링한 후에 전체적으로 전기적 특성의 재현성이 개선되었으며 Sensitivity( $R_{air}$/ $R_{gas}$)가 향상되었음을 확인하였다.하였다.석을 통하여 La의 분포를 확인하였으며, HRTEM 분석을 통하여 미세구조분석을 실시하였다.2463eV였다. 10K에서 광발광 봉우리의 919.8nm (1.3479eV)는 free exciton(Ex), 954.5nm (1.2989eV)는 donor-bound exciton 인 I2(DO,X)와 959.5nm (1.2921eV)는 acceptor-bound exciton 인 I1(AO,X) 이고, 964.6nm(1.2853eV)는 donor-acceptor pair(DAP) 발광, 1341.9nm (0.9239eV)는 self activated(SA)에 기인하는 광발광 봉우리로 고찰되었다.가 높을수록 방출전류가 시간에 따라 급격히 감소하였다. 각 duty비에서 방출전류의 양이 1/2로 감소하는 시점을 에미터의 수명으로 볼 때 duty비 대 에미터 수명관계를 구해 높은 duty비에서 전계방출을 시킴으로써 실제의 구동조건인 낮은 duty비에서의 수명을 단시간에 예측할 수 있었다. 단속적으로 일어난 것으로 생각된다.리 폐 관류는 정맥주입 방법에 비해 고농도의 cisplatin 투여로 인한 다른 장기에서의 농도 증가 없이 폐 조직에 약 50배 정도의 고농도 cisplatin을 투여할 수 있었으며, 또한 분리 폐 관류 시 cisplatin에 의한 직접적 폐 독성은 발견되지 않았다이 낮았으나 통계학적 의의는 없었다[10.0%(4/40) : 8.2%(20/244), p>0.05]. 결론: 비디오흉강경술에서 재발을 낮추기 위해 수술시 폐야 전체를 관찰하여 존재하는 폐기포를 놓치지 않는 것이 중요하며, 폐기포를 확인하지 못한 경우와 이차성 자연기흉에 대해서는 흉막유착술에 더 세심한 주의가 필요하다는 것을 확인하였다. 비디오흉강경수술은 통증이 적고, 입원기간이 짧고,