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        검색결과 22

        1.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, epoxy composites were reinforced with multi-walled carbon nanotubes and fused silica particles, dispersing the fillers within the epoxy resin based on a simple physical method using only shear mixing and ultrasonication. The hybrid composite specimens with 0.6 wt% of carbon nanotubes and 50 wt% of silica particles showed improved mechanical properties, with increase in tensile strength and Young’s modulus up to 12 and 37%, respectively, with respect to those of the baseline specimens. The experimental results showed that the low thermal expansion of the silica particles improved the thermal stability of the composites compared with that of the baseline specimen, whereas the thermal expansion slightly increased, due to the increased heat transfer from the exterior to the interior of specimens by the carbon nanotube filler. The coefficient of thermal expansion of the hybrid composite specimen reinforced with 0.6 wt% of carbon nanotubes and 50 wt% of silica particles was decreased by 25%, and the thermal conductivity was increased by about 84%, compared with those of the baseline specimen.
        4,500원
        2.
        2018.10 구독 인증기관·개인회원 무료
        Global climate change and increased international travel have affected the transmission of mosquito-borne diseases. In South Korea, uncommon diseases such as Dengue, chikungunya and Zika virus could be transmitted by potent mediator like Aedes albopictus. In order to cope with the risk of mosquito-borne diseases, rapid mosquito monitoring system is needed. Current mosquito monitoring procedures include installation of outdoor traps-mosquito collection-species classification-analysis of disease detection – upload of information to government research institutes – disease alert. In this process, species classification takes a lot of time, and if we reduce the time, we can cope with the disease outbreak more quickly. In this study, we developed automate species classification system target for 5 mosquito species (Culex pipiens, Cx. tritaeniorhynchus, Ae. albpictus, Ae. vexans, Anopheles spp.) disease vector live in South Korea. After modeling the morphology of each mosquito species, machine learning was carried out using DenseNet (Densely Connected Networks), one of the models of Artificial Neural Network. Using the learned model, we tested the classification of 5 species of mosquitoes and showed the accuracy from 97.35% to 99.48% at the maximum. Future research will focus on increasing the number of identifiable mosquito species and reducing the time spent on species classification. The autonomous classification of mosquito species using Deep Learning technology will contribute to the development of mosquito monitoring system and public health.
        4.
        2014.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We search for misclassified type 1 AGNs among type 2 AGNs identified with emission line flux ratios, and investigate the properties of the sample. Using 4 113 local type 2 AGNs at 0.02 < z < 0.05 selected from Sloan Digital Sky Survey Data Release 7, we detected a broad component of the Hα line with a Full-Width at Half-Maximum (FWHM) ranging from 1 700 to 19 090 km s−1 for 142 objects, based on the spectral decomposition and visual inspection. The fraction of the misclassified type 1 AGNs among type 2 AGN sample is 3.5%, implying that a large number of missing type 1 AGN population may exist. The misclassified type 1 AGNs have relatively low luminosity with a mean broad Hα luminosity, log LHα = 40.50 ± 0.35 erg s−1, while black hole mass of the sample is comparable to that of the local black hole population, with a mean black hole mass, log MBH = 6.94 ± 0.51 M⊙. The mean Eddington ratio of the sample is log Lbol/LEdd = −2.00±0.40, indicating that black hole activity is relatively weak, hence, AGN continuum is too weak to change the host galaxy color. We find that the Oiii lines show significant velocity offsets, presumably due to outflows in the narrow-line region, while the velocity offset of the narrow component of the Hα line is not prominent, consistent with the ionized gas kinematics of general type 1 AGN population.
        4,300원
        6.
        2011.10 KCI 등재 서비스 종료(열람 제한)
        Near-isogenic lines (NILs) carrying bacterial blight resistance genes (Xa4, xa5 and Xa21) were developed in japonica rice using Suweon345 as genetic background. NILs were selected by gene specific DNA markers and inoculation of K1 or K3a race. NILs conferring Xa4 were resistant to K1, K2, K3, and moderately resistant to K3a. NILs conferring xa5 were resistant to K1, K2, K3, and K3a. NILs having Xa21 were susceptible to K1, while resistant to K2, K3 and K3a. Target genes of NILs with the genetic background of Suweon345 were also confirmed by using eleven Philippines races and International Rice Bacterial Blight (IRBB) NILs carrying Xa4, xa5 and Xa21. All NILs had no significant difference from their recurrent parents in the major agronomic traits except for panicle length and brown rice 1,000 grain weight. Heading date of NILs ranged from Aug. 10 to Aug. 11, which was similar to that of recurrent parent, Suweon345. Culm length, number of grains per panicle and ratio of ripened grain of NILs were similar to those of Suweon345. Milled rice of NILs was ranged from 4.82 to 4.93MT/ha. These NILs will be useful for improving resistance to K3a race of bacterial blight pathogens in Korean japonica cultivars.
        11.
        2008.12 KCI 등재 서비스 종료(열람 제한)
        2003년에 이상적으로 많이 발생하여 벼에 심각한 피해를 가져온 혹명나방의 재배방법별, 엽록소 함량별 피해실태를 조사하여 피해에 따른 수량반응, 미질변화 등을 구명하고자 조사한 결과는 다음과 같다. 1. 혹명나방의 피해가 심할수록 벼의 등숙비율, 천립중의 감소와 복백립 등 미숙립의 증가에 따른 완전미 비율이 감소되어 완전미 수량이 피해가 심한 곳에서 36% 감소되었다. 2. 혹명나방의 피해가 심할수록 쌀의 외관상 품위가 떨어질 뿐만 아니라 단백질함량이 높아져 식미치는 감소되어 미질이 급격히 저하되었다. 3. 질소질 비료의 시용량이 증가할수록 혹명나방에 의한 피해는 증가하였으며, 특히 주남벼의 경우 질소량이 증가할수록 피해가 급증하였다. 4. 질소 시비량이 추천 시비량인 11 kg/10a를 초과시 피해엽율이 60% 이상으로 급증하였고, 60% 이상 피해를 입은 엽의 비율도 25%이상으로 늘어나 수량 감수 요인으로 작용하였다.
        13.
        2006.09 KCI 등재 서비스 종료(열람 제한)
        The effect of biofertilizer (compound of microbial inoculants or groups of micro-organisms) on growth and yield of rice was investigated. The experiment was carried out in a randomized complete block design with 3 replications and 7 treatments namely: RF=N-P2O5-K2O (11-5.5-4.8 kg 10a-1 ); half of the recommended fertilizer rate, HRF=N-P2O5-K2O (5.5-2.75-2.4 kg 10a-1 ); HRF+Bio 250=HRF combined with 250 kg biofertilizer 10a-1 ; HRF+Bio 500=HRF combined with 500 kg biofertilizer 10a-1 ; Bio 250=250 kg biofertilizer 10a-1 ; Bio 500=500 kg biofertilizer 10a-1 ; and NF = No Fertilizer. Results showed that the recorded values of plant height, tiller number and chlorophyll content at 40 to 60 days after transplanting (DAT) in HRF+Bio 500 were significantly higher than those recorded in the RF treatment. Similar observations between these two treatments were only recorded from 60 DAT onwards. Yield components were also superior in HRF+Bio 500 treatment and comparable to that of RF. The highest grain yield obtained in HRF+Bio 500 treatment (785.8 kg 10a-1 ) was statistically similar to that of RF (739.8 kg 10a-1 ) but significantly higher than that of NF (506.7 kg 10a-1 ). Finally, head grain recovery (90.9) was low while chalkiness (0.03) was high at HRF+Bio 500 treatment as compared with RF, which were (96.1) and (0.3), respectively. Results showed that combined treatment of HRF and 500 kg biofertilizer 10a-1 has similar effects on the growth and yield of rice with that of RF.
        14.
        2006.08 KCI 등재 서비스 종료(열람 제한)
        Hanmaeum is a new super-yielding japonica rice cultivar developed from a three-way cross of Mi1yang165,YR16365Acp13 and Iksan438 at Honam Agricultural Research Institute (HARI), RDA, in 2004. This cultivar has about 119 daysgrowth duration from transplant
        16.
        2003.06 KCI 등재 서비스 종료(열람 제한)
        The study of this experiment is focused on labor saving of healthy rice seedling production using PSF (polypropylene spunbonded fabrics) as thermal protection material. Several factors such as different compositions of nursery soil and PSF materials were tested to produce healthy rice seedlings. The inner thermal protection material in PE film (polyethylene film) showed 0.9-1.7~circC higher than that of PSF 40-100 ~textrmgm-2 . The light transmittance-ratio also showed similar trends. It is considered that the appropriate PSF material density was 40 gm~textrmgm-2 in accordance with economic values and healthy rice seedlings. Plant height and dry weight according to various nursery soil showed the rang-es of 8.5-14.2cm and 5.5-10.0mg, respectively. In composition of nursery soil, artificial soil combined with paddy soil was effective in producing healthy seedling for rice seedling production. The total sugar content also showed the difference between PSF 40, 60 ~textrmgm-2 PE film (0.43-0.52mg FW ~textrmg-1 ) and PSF 80, 100 ~textrmgm-2 (0.28-0.35mg FW ~textrmg-1 ) and it showed the same tendency among varieties as well as various nursery soil. These results demonstrate that PSF 40 ~textrmgm-2 economically affordable, and can be recommended as thermal protection material for producing good healthy rice seedling.
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