• 한국약용작물학회지
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• 제15권2호
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• pp.100-104
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• 2007

A protocol for the production of transgenic Panax ginseng C.A. Meyer was established via Agrobacterium tumefaciens-mediated genetic transformation of direct somatic embryos. A number of conditions related to the co-cultivation were tested with respect to maximizing transformation efficiency. The results showed that pH of the co-cultivation medium (5.7), the bacterial growth phase (optical density; $OD_{600}$ = 0.8), co-cultivation period (3 days), and acetosyringone concentration $(100\;{\mu}M)$ had positive effects on transformation. Selected plantlets were cultured on the medium at an elevated hygromycin level(30 mg/l). Integration of the transgenes into the P. ginseng nuclear genome was confirmed by PCR analysis using hpt primers and by Southern hybridization using hpt-specific probe. The transgenic plantlets were obtained after 3-month cultivation and did not show any detectable variation in morphology or growth characteristics compared to wild-type plants.

• Journal of Plant Biotechnology
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• 제3권3호
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• pp.113-121
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• 2001

The use of a marker gene in a transformation process aims to give a selective advantage to the transformed cells, allowing them to grow faster and better, and to kill the non-transformed cells. In general, the selective gene is introduced into plant genome along with the genes of interest. In some cases, the marker gene can be the gene of interest that will confer an agronomic characteristic, such as herbicide resistance. In this review we list and discuss the use of the most common selective marker genes on plant transformation and the effects of their respective selective agents. These genes could be divided in categories according their mode of action: genes that confer resistance to antibiotics and herbicides; and genes for positive selection. The contention of the marker gene flow through chloroplast transformation is further discussed. Moreover, strategies to recover marker-free transgenic plants, involving multi-auto-transformation (MAT), co-transformation, site specific recombination and intragenomic relocation of transgenes through transposable elements, are also reviewed.

• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2377-2386
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• 2021

To model the atmospheric dispersion of radionuclides released from nuclear accident is very important for nuclear emergency. But the uncertainty of model parameters, such as source term and meteorological data, may significantly affect the prediction accuracy. Data assimilation (DA) is usually used to improve the model prediction with the measurements. The paper proposed a parameter bias transformation method combined with Lagrangian puff model to perform DA. The method uses the transformation of coordinates to approximate the effect of parameters bias. The uncertainty of four model parameters is considered in the paper: release rate, wind speed, wind direction and plume height. And particle swarm optimization is used for searching the optimal parameters. Twin experiment and Kincaid experiment are used to evaluate the performance of the proposed method. The results show that the proposed method can effectively increase the reliability of model prediction and estimate the parameters. It has the advantage of clear concept and simple calculation. It will be useful for improving the result of atmospheric dispersion model at the early stage of nuclear emergency.

• Journal of Plant Biotechnology
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• 제49권1호
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• pp.61-73
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• 2022

In this study, we developed a reliable and efficient Agrobacterium-mediated genetic transformation system by applying sonication and vacuum infiltration to six chickpea cultivars (ICCV2, ICCV10, ICCV92944, ICCV37, JAKI9218, and JG11) using embryo axis explants. Wounded explants were precultured for 3 days in shoot induction medium (SIM) before sonication and vacuum infiltration with an Agrobacterium suspension and co-cultivated for 3 days in co-cultivation medium containing 100 µM/l of acetosyringone and 200 mg/l of L-cysteine. Responsive explants with putatively transformed shoots were selected using a gradual increase in kanamycin from 25 mg/l to 100 mg/l in selection medium to eliminate escapes. Results showed optimal transformation efficiency at a bacterial density of 1.0, an optical density at 600 nm wavelength (OD₆₀₀), and an infection duration of 30 min. The presence and stable integration of the β-glucuronidase (gusA) gene into the chickpea genome were confirmed using GUS histochemical assay and polymerase chain reaction. A high transformation efficiency was achieved among the different factors tested using embryo axis explants of cv. JAKI 9218. Of the six chickpea cultivars tested, JAKI9218 showed the highest transformation efficiency of 8.6%, followed by JG11 (7.2%), ICCV92944 (6.8%), ICCV37 (5.4%), ICCV2 (4.8%), and ICCV10 (4.6%). These findings showed that the Agrobacterium-mediated genetic transformation system will help transfer novel candidate genes into chickpea.

• 한국재료학회지
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• 제17권1호
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• pp.37-42
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• 2007

The effects of immersion time in the liquid nitrogen and deformation-induced martensitic transformation on the behavior of austenite stainless steels used for the hydrogen storage tank of auto-mobile at cryogenic temperature were investigated. With increasing of immersion time in the liquid nitrogen, the tensile strength of all austenite stainless steels at cryogenic temperature was increased because the martensite transformation of unstable austenite. The restraint of crack generation ana transmission also increased the tensile strength by the active ${\alpha}'$ transformation. The elongation decreasing of 321 steel is not the mechanical deformation of austenite phase but the stress induced martensite phase during the tensile test.

• 공업화학
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• 제3권3호
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• pp.522-526
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• 1992

반응온도 $10^{\circ}C$하에서 수산화칼슘 수용액에 $CO_2$ 가스를 흡수시켜 탄산화반응을 행하였으며 비정질탄산칼슘의 생성과 전이과정을 조사하였다. 생성된 비정질탄산칼슘은 입경 약 $0.02{\sim}0.05{\mu}m$ 정도인 구형의 초미립자로서 소량의 부착수를 포함고, $HCO^-_3$ 이온이 일부 치환된 비화학양론적인 물질이었다. 이 물질은 매우 불안정하여 반응액 내에서 쉽게 안정한 calcite로 전이하게 되는데 반응액 내의 탄산기가 $CO_3^{2-}$ 이온 지배적인 경우에는 연쇄상 calcite로 전이하였고, $HCO^-_3$ 이온 지배적인 경우에는 능면체 calcite로 전이하였다. 그러므로 비정질탄산칼슘의 전이과정을 적절히 제어함으로써 탄산칼슘 입자의 형태와 크기를 조절하는 것이 가능할 것으로 생각된다.

• Journal of Plant Biotechnology
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• 제3권3호
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• pp.135-140
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• 2001

An Agrobacterium tumefaciens LBA4404 (harboring antisense OMT gene)-mediated transformation method has been developed for poplar (P.nigra x maximowiczii) using prolonging co-cultivation time. Explants on LT (longterm) were induced transgenic calli one month earlier than those from ST (short-term) co-cultivation and remained healthier on LT than ST. With this approach, LT method reduced time to produce transgenic calli. Shoots were successfully regenerated from transgenic calli on SIM (Shoot Induction Medium) and rooted well on the basal medium spontaneously. The presence of antisense OMT gene was verified both by PCR and Southern analysis. Each transgenic poplar was phenotypically indishtinguishable when compared with controls for their growth pattern, leaf morphologies and xylem coloration.

• 한국측량학회지
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• 제28권2호
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• pp.281-287
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• 2010

본 연구에서는 지상레이저스캔 데이터의 보정을 위하여 변환 알고리즘을 비교하였다. 두 개 이상의 시점으로부터 취득된 스캔 데이터를 변환하는 데 많이 사용되는 pair-wise 변환은 오차가 누적된다. 스캔데이터간 보정에 많이 사용되는 ICP 알고리즘은 초기 기하정보가 필요하며, 여러 스캔데이터를 보정할 때 많은 기준점으로 인하여 동시에 보정하기 어렵다. 따라서 정합점을 이용한 글로벌 보정 방법을 수행하였다. 정합점은 SIFT를 이용하여 자동으로 강도영상으로부터 추출하였으며, GP 분석을 이용하여 글로벌 보정을 수행하였다. 제안된 글로벌 보정 방법은 연산속도, 정확도, 자동화 등에 있어서 장점을 지닌 것으로 나타났다. 본 연구의 성과를 이용하여 정합문제에 있어서 정확도와 속도를 적절히 고려한 보정방법을 개발할 수 있다.

• 한국기계가공학회지
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• 제20권9호
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• pp.97-103
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• 2021

In this paper, an omni wheel-based electric wheelchair is proposed that can achieve safe and convenient movement and can improve the convenience of living for mobility-impaired people who cannot move on their own. Generally, mobility-impaired people are afflicted with physical health issues such as pain and secondary body deformities because they often remain seated in wheelchairs for long periods of time. Hence, an electric wheelchair is required whose posture can be changed and whose size can be adjusted according to the user's body type. Such a wheelchair should also facilitate easy change of direction (even in a narrow space) for convenient movement. In this paper, an electric wheelchair featuring omni wheels is proposed that allows posture transformation and facilitates movement in a narrow space. It is believed that the proposed wheelchair can aid in enhancing the convenience of living for mobility-impaired people.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2004년도 생명공학 실용화를 위한 비젼
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• pp.183-183
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• 2004