• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.321-323
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• 2012

유기 발광 다이오우드는(OLEDs) 자체 발광 소자로써 높은 시야각, 높은 효율, 그리고 빠른 응답속도 등의 장점을 가지고 있어 차세대 디스플레이 및 조명 소자로서 많은 연구가 진행되고 있다. 특히 유기 발광 다이오우드는 차세대 반도체 조명 소자로서 조명의 패러다임을 바꿀 수 있는 기술로 인식되고 있다. 하지만, 유기 발광 다이오우드 조명의 상용화를 위해서는 가격 경쟁력을 갖추는 것이 시급하며, 이를 위해 저가 공정 개발이 필요하다. 본 연구에서는 유기발광 다이오우드 조명 제작에 필수적인 전면 전극 및 절연막 증착 공정을 기존의 노광 공정이 아닌 shadow mask 기술을 적용하여 형성하였다. 먼저 유리 기판 상에 150 nm 두께의 ITO 막을 shadow mask를 이용하여 증착하였다. 기존 공정에서는 노광 및 식각 공정을 이용하여 증착하는 것이 일반적이며, 광학적, 전기적 특성 또한 타 공정 방법에 비해 우수하다. 하지만 일련의 복잡한 공정으로 인해 제조 원가를 상승 시키는 단점이 있다. Fig. 1은 shadow mask를 이용하여 ITO를 증착을 수행한 공정의 모식도이다. ITO 박막 증착 후 표면 거칠기 제어 및 면저항 제어를 위해 O2 plasma 처리와 RTA 공정을 추가 수행하였다. Fig. 2(a)는 플라즈마 처리 및 열처리 공정 수행 후에 측정한 표면 AFM 사진이다. 열처리 및 플라즈마 처리 후에 ITO 박막의 표면 거칠기는 10배 이상 향상되었으며, 이는 유기 발광 다이오우드 조명 소자의 전면 투명 전극으로 사용되기에 적합한 값이다. 또한 전기적 특성 중 하나인 면저항 값은 열처리 및 플라즈마 처리 전/후의 값에서 많은 차이를 보인다. 표면 거칠기가 향상됨에 따라 면저항 값 역시 향상되는 결과를 보여주는데, 표면 처리전후의 면저항 값은 각각 28.17, 13.18 ${\Omega}/{\Box}$이다. 일반적으로 유기 발광 다이오우드의 전면 투명 전극으로 사용되기 위해서는 15 ${\Omega}/{\Box}$이하의 면저항 값이 필요한데, 표면 처리 후의 면저항값들은 이로한 조건을 만족한다. Fig. 3은 shadow mask 기술을 이용하여 절연막까지 형성한 유기 발광 다이오우드 소자의 전자 현미경 사진으로, 기존의 공정을 이용한 경우와 큰 차이는 없으며, 다만 shadow tail이 약 $30{\mu}m$ 정도 발생함을 확인할 수 있다. 절연막의 특성 평가 기준인 누설 전류 밀도는 $10-5A/cm^2$으로 기존의 공정을 이용한 경우에 비해 95% 수준으로서 shadow mask를 이용한 공정이 기존의 노광 및 식각 공정을 이용한 경우에 비해 공정 수는 9개가 단축됨에도 불구하고, 각 증착 박막의 특성에는 큰 차이가 없음을 알 수 있다.

• 한국산학경영학회:학술대회논문집
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• 2006.06a
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• pp.147-170
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• 2006

Landfill gas is a mixture of methane and carbon dioxide produced by the bacterial decomposition of organic wastes, and it is considered to produce bad smells and pollute the environment. Economic trials and the developments of landfill gas, as an alternative energy resource, become known at the recent years, Resource development of landfill gas, which is managed by Korea up to now, is for the most part generation using gas engine. Medium BTU and High BTU are considered for the power generation as well. Most income of generation using gas engine is selling charge through a power plant. Expecting to manage the power plant for up to 10 years, the analysis based on revenue and expenditure shows when the unit price is 65.2 Won and the operating rate reaches 90%, it is possible to be into the black in 2012 without considering additional financial expense, It was also analyzed that the profit at a unit price of 85 Won under the anticipated rising unit price by the operating rate of 71% is larger than at the operating rate of 90% under limited unit price of 65.2 Won. It means to manage the power plant at a unit price of 65.2 Won and the operating rate must be higher than 90% for economic logicality. If we assume that the operating rate is 90% and it increases the unit price, the unit price must be higher than 85 Won for the management of a power plant. Analysis of changing a unit price, however, might be expected to have a gradual rise of prices. If there is no price rising and additional income related to CDM(Clean Development Mechanism) and emission trading upon Kyoto protocol, the management of a power plant using gas engine will get financial difficulties because of many operating expenses. However, since landfill gas is considered as a worthy energy resource for the guarantee of sustainable development and for the equity between recent generation and future generation, the development of it must be accomplished by the government's additional supporting and efforts under the interest of all stakeholder who are involved.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.5
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• pp.62-72
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• 1995

공학분야에 널리 사용되고 있는 신뢰도 분석 방법 중에서 Monte Carlo simulation (MC), Mean-value First-Order Second-Moment Method(MFOSM), and Advanced First-Order Second-Moment(AFOSM) method들을 강물의 오염물질 농도와 수질기준치사이의 신뢰도 분석에 적용하였다. 미 환경 보건국에서 개발 보급한 QUAL2E를 이용하여 Mew Jersey에 위치한 Passaic강의 수질예측에서 4가지 주요인자(용존산소, 생물학적 산소요구량, 암모니아 그리고 조류)들이 정해진 수질기준치를 유지 할 수 있는 확률을 세가지 방법에 의해 추정한 후에 상호 비교하였다. MC방법에 의해 2,000회 simulation시켜서 그 결과가 시스템의 추계학적 성질을 잘 반영한 것으로 판단하여 비교기준으로 삼고 MFOSM과 AFOSM에 의해 추정한 결과와 비교하였다. MFOSM의 결과보다는 AFOSM의 결과가 전체적으로 MC의 결과에 더 근접하였으며, 이유는 AFOSM의 계산방법이 MFOSM의 선형근사로 인한 오차를 줄일 수 있었기 때문인 것으로 판단된다. MC방법의 결과와 다른 방법들의 결과사이의 차이가 입력 변수들이 평균값에서 멀어질 때가 많았는데 이는 MC의 경우 입력 변수들이 일정범위를 벗어나서 비현실적인 상황이면 model이 정지하는데, 다른 방법들은 simulation에 의한 것이 아니고 수학적인 계산에 의해서 신뢰도가 추정되기 때문에 이러한 상황이 반영될 수 없기 때문이다. 강물의 수질을 취급하는 공학적인 측면에서 보면, 이중에 가장 간편한 MFOSM이 많은 simulation이 필요한 MC나 계산방법이 상대적으로 복잡한 AFOSM에 비해 오차가 크지 않아서 이들을 대시하여 사용될 수 있다고 판단된다. 유래의 PAF가 분비된다는 것을 알 수 있었으며, 이러한 인자는 동결처리에서도 그 기능은 전혀 변하지 않는다고 본다. 이후에 있어서 mouse LIF의 첨가는 돼지의 수정란을 배반포 이후의 단계에까지 발달시킬 수 있었다. 있어서 더 적합한 것으로 판단되었다. 5. 개발된 모형은 논 관개의 물리적 측면과 관리목표 모두를 고려한 것으로 계산된 효율은 벼, 생육 각 단계에서의 효율 비교에 양호한 방법임을 알 수 있다.은 Sharpsburg 점질양토에 대한 S.C.S 한계허용치 10ton/ha/year 이내로 나타났다. 비처리구에서의 토양유실량은 평균 2.56ton/ha/year로 높게 나타난 반면 3개의 서로 다른 추리구인 비수구, 초생수로구 및 Bromegrass구에서는 각각 0.152, 0.192 및 0.290ton/ha/year로 낮은 결과를 가져왔다. 6. 평균 침전량에 대한 L.S.D. 검정 걸과 전시험구중 비처리구가 고도의 유의차를 나타낸 반면 비수구, 초생수로구 및 Bromegrass 목초구 간에는 아무런 유의차가 인정되지 않았다. 7. 농지보전 처리구인 배수구와 초생수로구는 비처리구에 비해 낮은 침두 유출량과 낮은 토양유실량을 나타내었다.구보다 14% 절감되는 것으로 나타났다.작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at% U, 66.4 at% O의 결과를 얻었다. 산화물 핵연료의 표면 관찰 및 정량 분석 시험시 시편 표면을 전도성 물질로 증착시키지 않고, Silver Paint 에 시편을 접착하는 방법으로도 만족한 시험 결과를 얻을 수 있었다.째, 회복기 중에 일어나는 입자들의 유입은 자기폭풍의 지속시간을 연장시키는 경향을 보이며 큰 자기폭풍일수록 현저했다. 주상에서 관측된 이러한 특성은 서브스톰 확장기 활동이 자기폭풍의 발달과 밀접한 관계가

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.1
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• pp.38-46
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• 1999

o.25${\mu}m$ T-shaped gate P-HEMT is fabricated and used for design of X0band three stage monolithic microwave integrated circuit(MMIC) low noise amplifier(LNA). The fabricated P-HEMT exhibits an extrinsis transconductance of 400mS/mm and a drain current of 400mA/mm. The RF and noise characteristics show that the current gain cut off frequency is 65GHz and minimum noise figure(NFmin) of 0.7dB with an associated gain of 14.8dB at 9GHz. In the design of the three stage LNA, we have used the inductive series feedback circuit topology with the short stub. The effects of series feedback to the noise figure, the gain, and the stability have been investigated to find the optimal short stub length. The designed three staage LNA showed a gain of above 33dB, a noise figure of under 1.2dB, and ainput/output return loss of under 15dB and 14dB, respectively. The results show that the fabricated P-HEMT is very suitable for a X-band LNA with high gain.

• Journal of Korean Foot and Ankle Society
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• v.6 no.1
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• pp.40-45
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• 2002

Purpose: To analyze the radiographic results between the simple bone excision and simple bone excision and posterior tibial tendon advancement for prehallux. Materials and Methods: Thirty-four patients who underwent operative treatment for prehallux between 1995 and 2000 were reviewed. Twenty-six patients who underwent simple bone excision and posterior tibial tendon advancement and eight patients who underwent simple bone excision were available for follow-up. Follow-up averaged 44 months(15-59 months). We evaluated and compared the cuboidal height and the talo-1st metatarsal angle in the preoperative and postoperative radiography. Results: The average span of disappearing pain is 3.7 months(2-7 months) after the operation. Mean cuboidal height and talo-1st metatarsal angle were increased $6.7{\pm}1.8mm$, $5.0{\pm}2.1^{\circ}$ before to $7.8{\pm}0.2mm$, $5.6{\pm}0.7^{\circ}$ after simple bone excision and posterior tibial tendon advancement. Mean cuboidal height and talo-1st metatarsal angle were increased $6.6{\pm}0.7mm$, $4.6{\pm}1.1^{\circ}$ before to $7.7{\pm}0.9mm$, $5.1{\pm}0.4^{\circ}$ after simple bone excision and posterior tibial tendon advancement. One case of extra-osseous migration of the Mitek anchor inserted into navicula was seen during the follow-up period. Conclusion: This study shows that the remarkable differences between the two procedures are not found. So, simple bone excision without advancement of posterior tibial tendon for prehallux can generate relatively good results.

• Journal of Life Science
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• v.9 no.4
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• pp.439-452
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• 1999

This study was designed to investigate the effects of sea tangle (Laminaria japonica) extract and fucoidan components on anti-aging action. Sprague-Dawley(SD) male rats (210$\pm$5g) were fed experimental diets Dasi-Ex group: sea tangle extract powder of 4.0% added to control diet; Fuco-I, II and III groups: funcoidan powder of 1, 2 and 3% added to Dasi-Ex group for 45 days. Hydroxyl radical (.OH) formations were significantly inhibited (10-20% and 25-30%) in serum and brain mitochondria of Dasi-Ex and Fuco-I, II and III groups compared with control group. Significant differences in .OH formations of brain mitochondria in Dasi-Ex and Fuco-I groups could not be obtained, but.OH formations of brain microsomes resulted in a significant decrease (15-20%) in Fuco-II and III groups compared with control group. Basal oxygen radical (BOR) formations were significantly decreased about 10% and 13-15% in brain mitochondria of Dasi-Ex and Fuco-I group, and Fuco-II, III groups, and also decreased about 10% and 15-20% in brain microsomes of Dasi-Ex and Fuco-I groups, and Fuco-II, III groups. LPO levels of brain mitochondria and microsomes were significantly inhibited about 10% in Dasi-Ex and Fuco-I, II groups and 15% in Fuco-III groups. Oxidized proteins (>C=O) were significantly inhibited about 10% in serum of Dasi-Ex and Fuco-I, II, III groups and brain mitochondria of Dasi-Ex group, while remarkably inhibited (30~35%) in brain mitochondria of Fuco-I, II and III groups. Nitric oxide (NO) levels were significantly inhibited (12~15%) in serum of Fuco-I, II and III groups, but there no significant difference in serum NO levels of Dasi-Ex group. Superoxide dismutase (SOD) activities were remarkably increased (30~ 60%) in serum of Fuco-I, II and III groups, but there were no significant differences in SOD activities in serum of Dasi-Ex group. Catalase (CAT) activities were significantly increased about 20% in serum of Dasi-Ex and Fuco-I, II, III groups. Mn-SOD activities in brain mitochondria were significantly increased about 17% in Dasi-Ex group, while remarkably increased 26~36% in Fuco-I, II, III groups. Cu,Zn-SOD activities in brain cytosol were dose-dependently of fucoidan increased 10%, 12% and 18%, respectively, compared with control group. These results suggest that anti-aging effects of fucoidan may play a pivotal role in attenuating a various age-related changes such as chronic degenerative disease and senile dementia.

• The Journal of the Petrological Society of Korea
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• v.15 no.1 s.43
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• pp.25-38
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• 2006

Metamophic rocks of Samcheog area, northeastern Yeongnam massif, was studied petrochemically. This area includes Precambrian Hosanri Formation (schists and gneisses) and granitoid (Icheon granitic gneiss, leucocratic granite and Hongjesa granite), Cambrian sedimentary rocks, and Cretaceous sedimentary and acidic volcanic rocks. Hosanri formation is composed of quartz+plagioclase+K-feldspar+biotite+muscovite+granet${\pm}$cordierite${\pm}$sillimanite. Mineral assemblage of biotite granitic gneiss, which is massive granodioritic rock with weak foliation, is similar to Hosanri formation. According to mineral assemblages, metamorphic rocks of studied area can be divided into two metamorphic zones (garnet and sillimanite zones). From Icheonri area, major, trace and rare earth element data of biotite granitic gneiss and luecocratic granite suggest that source rock is politic rocks of Hosanri formation and source magma was formed by anatexis and experienced fractionation of plagioclase. Trace element diagram show collisional environment such as syn-collisional, volcanic arc granite. Orientation of faults in study area have three maximum concentrations, $N54^{\circ}\;W/77^{\circ}\;SW,\;N49^{\circ}\;W/81^{\circ}\;NE\;and\;N10^{\circ}\;W/38^{\circ}\;NE$. Structure analysis suggests that faults in study area ware formed by uplift and compression. Faulting age is guessed after Tertiary because some shear joints is developed in dikes to intrusive Cretaceous acidic volcanic rock. Hosanri formation and Icheon granitic gneiss had experienced similar deformation history because they have maximum concentration to foliations, $N89^{\circ}\;E/55^{\circ}\;SE\;and\;N80^{\circ}\;E/45^{\circ}\;SE$, respectively.

• The Journal of the Korean Society for Microbiology
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• v.21 no.1
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• pp.151-161
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• 1986

In order to develop sensitive and sepcific assay methods for E. coli heat labile enterotoxin(LT) hybridoma cell lines secreting LT specific monoclonal antibody were obtained. LT was purified from cell lysate of E. coli O15H11. The steps included disruption of bacteria by French pressure, DEAE Sephacel ion exchange chromatography, Sephadex G200 gel filtration, and second DEAE Sephacel ion exchange chromatography, successively. Spleen cells from Balb/c mice immunized with the purified LT and $HGPRT^{(-)}$ plasmacytomas, $P3{\times}63Ag8.V653$ were mixed and fused by 50% (w/v) PEG. Hybrid cells were grown in 308 wells out of 360 wells, and 13 wells out of them secreted antibodies reacting to LT. Among these hybridoma cell 1G8-1D1 cell line was selected since it had produced high-titered monoclonal antibody continuously. By using culture supernatant and ascites from 1G8-1D1 cells the monoclonal antibody was characterized, and an assay system for detecting enterotoxigenic E. coli was established by double sandwich enzyme-linked immunosorbent assay (ELISA). The following results were obtained. 1. Antibody titers of culture supernatant and ascites from 1G8-1D1 hybridoma cells were 512, and 102, 400, respectively by GM1-ELISA and its immunoglobulin class was IgM. 2. The maximum absorption ratio of 1G8-1D1 cell culture supernatant to LT was 90% at $300\;{\mu}g/ml$ of LT concentration. LT concentration shown at 50% absorption ratio was $103.45{\mu}g$ and the absorption ratio was decreased with tile reduction of LT concentration. This result suggests that monoclonal antibody from 1G8-1D1 hybridoma cell bound with LT specifically. 3. The reactivities of 1G8-1D1 cell culture supernatant to LT and V. cholerae enterotoxin(CT) were 0.886 and 0.142(O.D. at 492nm) measured by the GM1-ELISA, indicating 1G8-1D1 monoclonal antibody reacted specifically with LT but not with CT. 4. The addition of 0.1ml of ascites to 0.6mg and 0.12mg of LT decreased the vascular permeability factor to 41% and 44% respectively, but it did not completely neutralize LT. 5. By double sandwich ELISA using monoclonal antibody, as little as 75ng of the purified LT per ml could be detected. 6. The results by assay of detecting LT in culture supernatants of 14 wild strains E. coli isolated from diarrhea patients by the double sandwich ELISA were almost the same level as those by reverse passive latex agglutination.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.6
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• pp.49-59
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• 2018

The purpose of this study was to analyze the importance and satisfaction of resources in the mouth of Nakdong River. A Pearson's chi-square test was performed in SPSS 24.0 for statistical analysis and the result of the study was summarized by three points. First, the results of importance analysis on resources in Nakdong estuary found that the importance of ecology resources was the highest with 27.1%, followed by landscape resources (18.5%), waterside leisure resources (6.5%), complex cultural resources (5.4%), and historic and cultural resources (3.3%). The probability values (p-value) of each group had shown significant differences depending on gender, age, and the location of the survey. For instance, women respondents reported a higher preference to ecology resources and complex cultural resources such as museums than men respondents as much as two times and three times, respectively. Meanwhile, men respondents showed a higher preference to waterside leisure resources in three times as much as women respondents. As for the analysis by age, the respondents in their 20s and 30s recorded a higher value than those in other age groups, and people in their 30s reported a higher preference to waterside leisure resources than those in different age groups by three times. Lastly, no significant differences were found in the preference analysis by occupation (p>.05). With regard to the results of satisfaction analysis, the average level of satisfaction on landscape resources was 6.01, and that of ecology resources and complex cultural resource were 5.65 and 5.15, respectively. Also, significant differences were found between landscape and ecology resources in the satisfaction analysis by age, landscape resources by age, ecology resources by region, and between landscape resources and ecology resources by occupation. The p-value of complex cultural resources was p=0.012, although the satisfaction level of landscape resources and ecology resources were reported to have no significant differences by age. As for the level of satisfaction in landscape resources, respondents in their 40s and 50s showed a high level of satisfaction. However, those in their 20s showed a relatively low level of satisfaction in the same category. The survey respondents living in Busan and South Gyeongsang Province and those living outside the regions revealed no significant differences in terms of satisfaction in landscape resources and complex cultural resources. However, the two same groups were found to show significant differences in the satisfaction analysis on ecology resources. In the satisfaction analysis of landscape resources and ecology resources by occupation, significant differences were found among college students, government employees, ordinary citizens, and expert groups. However, they showed no significant differences in the level of satisfaction to complex cultural resources. Third, the results of importance-satisfaction analysis on Nakdong estuary found that the average levels of satisfaction to landscape resources for each group of respondents who considered landscape, ecology, and cultural resources as important was 6.19, 6.08, and 5.67, respectively. Their levels of satisfaction on ecology resources were 5.95, 5.57, and 5.41 for each. Its correlation to the importance was insignificant. However, it was confirmed that the correlation to the level of satisfaction on complex cultural resources had a significant difference (p=0.025). In addition, the results of the analysis on 15 detailed items that was carried out with the aim to improving values and vitalizing resources in the mouth of Nakdong River found that respondents considered that the vitalization of eco-tourism (49.5%) and restoration of reed marsh (47.5%) were important. The results of detailed analysis revealed respondents' high awareness on the need of enhancing values on ecology resources. Also, improving infrastructure nearby the mouth, creating cycling routes, walkways, waterside leisure facilities, and others were considered as the requirements for the vitalization of Nakdong estuary.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.3
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• pp.203-213
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• 2017

This study investigated the changes in yields, antioxidant compounds, and antioxidant activities among 11 adzuki bean cultivars cultivated in a paddy field with somewhat poorly drained soil. The adzuki bean cultivars were cultivated in the paddy field from 2015 to 2016 in Milyang, Gyeongsangnam, Korea. Average soil moisture content was 16.5% in 2015 and 31.0% in 2016 at the experimental site during adzuki bean cultivation. As the soil moisture content increased, most of the adzuki bean cultivars showed deceases in stem height, first setting pod node, number of pods, 100 seed weight, and yield. Chungju-pat produced the greatest yields among the 11 cultivars in 2015 and 2016, whereas Hongeon had the smallest yields. Adzuki bean yields after paddy field cultivation was lower for all cultivars than for adzuki bean yields from the same cultivars after upland field cultivation. Chungju-pat and Chilbo-pat showed the smallest decreases in yields after paddy field cultivation, whereas Hongeon and Kumsil showed the greatest yield reductions. There were no significant differences in proximate composition. Some mineral components ($P_2O_5$, Ca, and Mg) were statistically different across cultivars. Chungju-pat had the highest Ca and Mg contents, but antioxidant components (polyphenol and flavonoids) and antioxidant activities (ABTS and DPPH) were highest in Saegil and lowest in Jungbu-pat. PCA and clustering analyses, based on the growth, yield, and antioxidant component measurements, performed to identify which variables contributed the most to separating adzuki bean cultivars or to grouping cultivars with similar characteristics. These analyses showed that the antioxidant components and antioxidant activities had the most influence on grouping cultivars together. Among the 11 cultivars, Saegil was statistically different from the other cultivars, but the other 10 cultivars were not significantly different under paddy field cultivation. Soil moisture content affected adzuki bean yield and antioxidant component contents. An increase in soil moisture led to a decrease in yield, but an increase in antioxidant components. These results provide information that will improve the selection of an appropriate adzuki bean cultivar for use in paddy fields.