• Title/Summary/Keyword: $F_2$-hybrid

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Speciation of Viola albida var. takahashii based on both artificial and natural hybridization between V. albida var. albida and V. albida var. chaerophylloides

  • Songhee AHN;Sung Soo WHANG
    • Korean Journal of Plant Taxonomy
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    • v.52 no.4
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    • pp.226-234
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    • 2022
  • The study aims are to examine the characteristics of artificial and natural hybrids between Viola albida var. albida (= albida, from below) and V. albida var. chaerophylloides (= chaerophylloides, from below), and to confirm if hybrids could be fertile and make populations in their native habitats. The 1st filial (= F1, from below) leaf shape produced by artificial crossing between albida and chaerophylloides was the same as that of V. albida var. takahashii (= takahashii, from below), and F1 bore also both chasmogamous and cleistogamous flowers. F1 seed number was 9.6 per cleistogamous pods, which was remarkably less than the average of 38.2 for albida and chaerophylloides, but the germination rate was all similar. The leaf type of self-crossed 2nd offsprings (= F2, from below) showed all leaf types found in the Viola albida complex, but the ratio of chaerophylloides leaf type was relatively low. Individuals whose F2 leaf type was restored to albida produced an average of 31.4 seeds per capsule, meaning that fertility was restored. On the other hand, individuals of F2 takahashii leaf type come to fruition a low average of 10.4 seeds per capsule, which is similar to that of takahashii. The results of crossbreeding experiment, where is their native habitats, were similar to that of laboratory. Both albida and chaerophylloids in Mt. Bulmyeong distribute extensively, but takahashii make a small population only in places where albida and chaerophylloides grow together. Summarizing the above results is suggesting that the speciation of takahashii was done by hybrid between albida and chaerophylloides, and these have been maintained with relatively small population by cleistogamous capsules.

Development of a Robust Polyvoltine Breed $'NP_1'$ of the Mulberry Silkworm, Bombyx mori L.

  • Singh Ravindra;Rao D. Raghavendra;Sharma S.D.;Chandrashekaran K.;Basavaraja H.K.;Kariappa B.K.;Dandin S.B.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.12 no.1
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    • pp.29-34
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    • 2006
  • A breeding programme was initiated during 2001 utilizing two polyvoltine silkworm breeds viz. $BL_{69}$, an evolved breed tolerant to high temperature and MAR, comparatively resistant to Bombyx mori nuclear polyhedrosis virus (BmNPV) with the objective to develop robust polyvoltine breeds and hybrids. The breed $NP_1$ was developed by exposing the fifth instar larvae to high temperature $(36{\pm}1^{\circ}C)$, high Relative Humidity ($85{\pm}5%$ R.H.) and inoculating third instar larvae with BmNPV inoculum. At $F_{12}$, the breed was tested for hybrid forming ability utilizing six bivoltine silkworm breeds viz. $CSR_2,\;CSR_4,\;CSR_{17},\;CSR_{18},\;CSR_{19}\;and\;NB_4D_2$. The hybrid $'NP_1{\times}CSR_{17}'$ exhibited its superiority by recording 97.2% survival, 1.892 g cocoon weight, 0.406 g cocoon shell weight, 21.5% cocoon shell ratio, 16.6% raw silk percentage and 890 m filament length whereas the control $(PM{\times}CSR_2)$ has recorded 90.2% survival, 1.599 g cocoon weight, 0.304 g cocoon shell weight, 18.9% cocoon shell ratio, 13.1 % raw silk percentage and 768 m filament length. Commercial exploitation of the new $polyvoltine{\times}bivoltine$ hybrid in sericulture industry has been discussed.

Screening of Resistant Lines and Yield Losses to F1 Corn from Feeding by the Aphid and Mite (진딧물과 응애 가해에 의한 옥수수 F1의 수량감소율 과 저항성계통 선발)

  • Lee, Joon-Soo;Kim, Soon-Kwon
    • Korean Journal of Breeding Science
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    • v.42 no.5
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    • pp.555-564
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    • 2010
  • Aphid and mite are the major insects that harm corn. These insects are difficult to control because they are very sensitive to environmental conditions. The purpose of this experiment was to information the loss in quantity of corn and to select inbred lines with resistance after exposing corn to aphid and mite. When exposed to aphid, the average loss in grain yield, ear length, ear diameter, 100 kernel weight, kernel length, kernel width, and kernel thickness were 18.4, 10.9, 1.7, 5.4, 2.3, 1.5 and -0.2%, respectively. When exposed to mite, the average loss in grain yield, ear length, ear diameter, 100 kernel weight, kernel length, kernel width, and kernel thickness were 49.7, 16.5, 20.7, 18.9, 9.5, and -3.4, respectively. Mite had more significant impact on the loss than aphid. Among these factors, grain yield and ear dimater were most significantly correlated on the loss to aphid ($r=0.83^{**}$), while kernel length and thickness were most significantly correlated on the loss to mite ($r=0.83^{**}$). However, ear length was not related to loss to the two insects. The inbred lines that were often used for $F_1$ hybrid which was lower than the average loss by aphid, were KS7, B68, 61B3, 70A1, and KS5, while the inbred lines that were often used for $F_1$ hybrid which was lower than the average decrease by mite, were KS7, B68, 61B3, 66B2-4, 70A1, 72B2, and KS5. These inbred lines could be used to breed inbred lines, hybrid, and open pollination variety that confer resistant to aphid and mite.

The Effect of Multilayer Passivation Film on Life Time Characteristics of OLED Device (OLED소자의 수명에 미치는 다층 보호막의 영향)

  • Ju, Sung-Hoo;Yang, Jae-Woong
    • Journal of the Korean institute of surface engineering
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    • v.45 no.1
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    • pp.20-24
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    • 2012
  • Multilayer passivation film on OLED with organic/inorganic hybrid structure as to diminish the thermal stress and expansion was researched to protect device from the direct damage of $O_2$ and $H_2O$ and improve life time characteristics. Red OLED doped with 1 vol.% Rubrene in $Alq_3$ was used as a basic device. The films consist of ITO(150 nm)/ELM200_HIL(50 nm)/ELM002_HTL(30 nm)/$Alq_3$: 1 vol.% Rubrene(30 nm)/$Alq_3$(30 nm) and LiF(0.7 nm)/Al(100 nm) which were formed in that order. Using LiF/$SiN_x$ as a buffer layer was determined because it significantly improved life time characteristics without suffering damage in the process of forming passivation film. Multilayer passivation film on buffer layer didn't produce much change in current efficiency, while the half life time at 1,000 $cd/m^2$ of OLED/LiF/$SiN_x$/E1/$SiN_x$ was 710 hours which showed about 1.5 times longer than OLED/LiF/$SiN_x$/E1 with 498 hours. futhermore, OLED/LiF/$SiN_x$/E1/$SiN_x$/E1/$SiN_x$ with 1301 hours showed about twice than OLED/LiF/$SiN_x$/E1/$SiN_x$ which demonstrated that superior characteristics of life time was obtained in multilayer passivation film. Through the above result, it was suggested using LiF/$SiN_x$ as a buffer layer could reduce the damage from the difference of thermal expansion coefficient in OLED with protective films, and epoxy layer in multilayer passivation film could function like a buffer between $SiN_x$ inorganic layers with relatively large thermal stress.

A New Early Maturing, High Yielding and High Oleic Acid Rapeseed (Brassica napus L.) of F1 Hybrid "Boram" (조숙, 다수성, 올레인산 고함유 유채 신품종 "보람")

  • Kim, Kwang-Soo;Jang, Young-Seok;Lee, Yong-Hwa;Bang, Jin-Ki;Suh, Sae-Jung
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.664-668
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    • 2009
  • "Boram" is a new $F_1$ hybrid of rapeseed (Brassica napus L.) with early maturing, high yield and high oleic acid. This cultivar was developed from the cross between Mokpo-CGMS (male steile line) and 8634-B-1-3-1-8 (restore line) for the production of edible oil and biodiesel in 2006. Yield trials were conducted from 2007 to 2008 and regional adaptation trials were examined at four locations in 2008. "Boram" has green and parted leaf, yellowish flower, and black seed coat. The ripening period of "Boram" is similar to "Sunmang", but 3 days faster than "Tammiyuchae". The average seed yield of the regional adaptation trials was 424 kg/10a, which was 11 and 48% higher than "Sunmang" and "Tammiyuchae" variety. Total oil content of "Boram" was 44.2%. In fatty acid composition, "Boram" has no erucic acid. However, oleic acid content is 68.5%, which is 3.7 and 5.4% higher than "Tammiyuchae" and "Sunmang". And total glucosinolate content was 2.27mg/g. Therefore this variety is recommended as a leading variety at southwestern areas including Jeonnam, Jeonbuk and Kyeongnam provinces and Jeju island of Korea.

Advanced Water Treatment of High Turbidity Source by Hybrid Process of Multi-channels Ceramic Microfiltration and Activated Carbon Adsorption (다채널 세라믹 정밀여과 및 활성탄 흡착 혼성공정에 의한 고탁도 원수의 고도정수처리)

  • Park, Jin-Yong;Lee, Hyuk-Chan
    • Membrane Journal
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    • v.18 no.4
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    • pp.325-335
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    • 2008
  • In this study, we used multi-channels ceramic membrane having larger permeate volume per unit time rather than tubular membrane. The hybrid process for advanced drinking water treatment was composed of granular activated carbons (GAC) packing between module inside and outside of multi-channels microfiltration membrane. Instead of natural organic matters (NOM) and fine inorganic particles in natural water source, modified solution was prepared with humic acid and kaolin. Kaolin concentration was fixed at 30mg/L and humic acid was changed as $2{\sim}10\;mg/L$ to inspect effect of organic matters. As a result, both resistance of membrane fouling ($R_f$) and permeate flux (J) were highly influenced by concentration of humic acid. Also, in result of water-back-flushing period (FT) effect, the shorter FT was the more effective to reduce membrane fouling and to enhance permeate flux because of frequent water-back-flushing. However, the optimal FT condition was 8 min when operating costs were considered. Then, the hybrid process using multi-channels ceramic membrane and GAC was applied to lake water treatment. As a result, average treatment efficiencies in our experiment using the hybrid process were 98.02% for turbidity, 75.64% for $UV_{254}$ absorbance, 7.18% for TDS and 84.73% for $COD_{Mn}$.

Effect of Vinyl Ethylene Carbonate on Electrochemical Characteristics for Activated Carbon/Li4Ti5O12 Capacitors (활성탄/리튬티탄산화물 커패시터의 전기화학적 특성에 미치는 비닐에틸렌카보네이트의 영향)

  • Kwon, Yong-Kab;Choi, Ho-Suk;Lee, Joong-Kee
    • Journal of the Korean Electrochemical Society
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    • v.15 no.3
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    • pp.190-197
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    • 2012
  • We employed the vinyl ethylene carbonate (VEC) as an electrolyte additive and investigated the effect of the electrolyte additive on the electrochemical performance in hybrid capacitor. The activated carbon was adopted as cathode material, and the $Li_4Ti_5O_{12}$ oxide was used as anode material. The electrolyte was prepared with the $LiPF_6$ salt in the mixed solvent of ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate(EMC). We evaluated the electrochemical performance of the hybrid capacitor with increasing the amount of the VEC electrolyte additive, which is known as the remover of oxygen functional group and the stabilizer of the electrode by reducing the surface of electrode, and obtained the superior performance data especially at the addition of the VEC electrolyte additive of around 0.7 vol%. On the contrary, the addition of the VEC more than 0.7 vol% in the electrolyte leads to the degradation in electrochemical performance of hybrid capacitor, suggesting the increase of the side reaction from the excessive VEC additive. X-ray photoelectron spectroscopy (XPS) revealed that the addition of the VEC suppressed the formation of LiF component, which is known as the insulator, on the surface of electrode. The optimized addition of VEC exhibited the improved capacity retention around 82.7% whereas the bare capacitors without VEC additive showed the 43.2% of capacity retention after 2500 cycling test.

Optical system design for compact digital still camera using diffractive optical elements (회절광학소자를 이용한 컴팩트 디지털 스틸 카메라용 광학계 설계)

  • 박성찬
    • Korean Journal of Optics and Photonics
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    • v.11 no.4
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    • pp.239-245
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    • 2000
  • In this paper, the fundamental properties of diffractive optical element were investigated. Also, this work deals with theoretical approaches for achromatization in DOE's optical system based on thin lens theory. It is found that achromatization could be satisfied by one hybrid lens only, which is composed of a diffractive and a refractive element. In order to have compact optical system, we used the tele-photo type lens composed of a positive and a negative power elements instead of retro-focus lens. From the Gaussian brackets and Seidel aberration theory, the initial design was numerically obtained. The aberration properties of an initial design was aplanat and flat field. In order to correct the chromatic aberrations, refractive and diffractive elements were used on front element. This hybrid lens is also useful for correction of higher order aberrations. Compared to conventional design composed of refractive lenses only, this approach dramatically improved the compactness of the optical system. Finally, residual aberration balancing results in a lens with focal length of 3.89 mm and overall length of 5.19 mm, which has enough performance over an f-number of 4.0. Also, it is expected to fulfill all the requirements of a digital still camera lens. This optical system is superior to the current refractive lens system in the number of elements, weight, and aberration properties. rties.

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Performance Analysis of PE-GOX Hybrid Rocket Motor Part I : Regression Rate Characteristics (PE-GOX 하이브리드 로켓 모터의 성능 예측 Part I : 후퇴율 특성)

  • Youn, Chang-Jin;Song, Na-Young;Yoo, Woo-Jun;Jeon, Chang-Soo;Kim, Jin-Kon;Sung, Hong-Gae;Moon, Hee-Jang
    • Journal of the Korean Society of Propulsion Engineers
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    • v.11 no.2
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    • pp.71-78
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    • 2007
  • An experimental investigation was conducted to clarify the combustion characteristics of Polyethylene-GOX(PE-GOX) hybrid motor using a single-port fuel grain configuration. Data from the experiments were analyzed to evaluate the length-averaged regression rate of PE-GOX propellants. Based on the existing theories, the empirical regression rate formulas provided from Marxman[3,4] and Altman[14] showed good concordance with the PE-GOX experiments. The accuracy of the regression rate was then evaluated and compared with the measured one. As a result, Marxman's model was somewhat more precise than Altman's model in these experiments. Moreover, the consideration of the empirical regression rate showed that O/F ratio has minor variation due to the quasi constant inflow of the fuel during motor firing.

Hybrid Neural Classifier Combined with H-ART2 and F-LVQ for Face Recognition

  • Kim, Do-Hyeon;Cha, Eui-Young;Kim, Kwang-Baek
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1287-1292
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    • 2005
  • This paper presents an effective pattern classification model by designing an artificial neural network based pattern classifiers for face recognition. First, a RGB image inputted from a frame grabber is converted into a HSV image which is similar to the human beings' vision system. Then, the coarse facial region is extracted using the hue(H) and saturation(S) components except intensity(V) component which is sensitive to the environmental illumination. Next, the fine facial region extraction process is performed by matching with the edge and gray based templates. To make a light-invariant and qualified facial image, histogram equalization and intensity compensation processing using illumination plane are performed. The finally extracted and enhanced facial images are used for training the pattern classification models. The proposed H-ART2 model which has the hierarchical ART2 layers and F-LVQ model which is optimized by fuzzy membership make it possible to classify facial patterns by optimizing relations of clusters and searching clustered reference patterns effectively. Experimental results show that the proposed face recognition system is as good as the SVM model which is famous for face recognition field in recognition rate and even better in classification speed. Moreover high recognition rate could be acquired by combining the proposed neural classification models.

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