• 미생물학회지
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• 제27권2호
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• pp.92-97
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• 1989

the vector, pGUR19, for Rhizobium gene manipulation, was constructed by combining the replication and mobilization function of indigenous multicopy plasmid from Acacia(Robinia pseudoacacia L.) Rhizobia sp86 with E. coli cloning vehicle, pBR322. The vector could be efficiently mobilized by RP4 tra function incorporated into chromosome of E. coli named SM10 and efficiently transferred to various gram negative hosts including Rhizobium and Afrobacterium by transformation. Mobilization frequency of the constructed vector was ranged from $1.2\times 10^{-2}$ (E.coli HB 101) to $4.6\times 10^{-4}$ (A. tumefaciens 15955) and transformation frequency was ranged from $5.4\times 10^{-7}$(E. coli HB101) to $1.2\times 10^{-10}$ (A. tumefaciens 15955). The vector, pGUR19, was stably replicated and maintained in a variety of Rhizobium and Agrobacterium.

• 정보처리학회논문지A
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• 제9A권1호
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• pp.37-44
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• 2002

기존의 순차 프로그램에서 병렬성을 추출하는 연구들은 하나의 프로시저 내 변환에 치중되고 있다. 그러나 대부분의 프로그램들은 프로시저간 잠재된 병렬성을 가지고 있다. 본 논문에서는 자료 종속성 제거방법을 이용하여 프로시저 호출을 가진 루프에서 병렬성 추출 방식을 제안한다. 프로시저 호출을 포함하는 루프의 병렬화는 대부분 자료종석거리가 uniform 형태의 코드에서만 연구되었다. 본 논문에서는 자료종속거리가 uniform 코드와 nonuniform 코드에 대해 모두 적용 가능한 프로시저 간 변환 방법을 제시하였으며, 제시된 알고리즘의 성능평가를 위하여 CRAY T3E에서 성능평가하였고, 제시된 방법이 효과적임을 보였다.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2005년도 e-Biz World Conference 2005
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• pp.3-7
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• 2005

• 대한수학회논문집
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• 제9권4호
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• pp.881-889
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• 1994

Let ($X, \Beta, \mu$) be a measure space with the $\sigma$-algebra $\Beta$ and the probability measure $\mu$. Throughouth this article set equalities and inclusions are understood as being so modulo measure zero sets. A transformation T defined on a probability space X is said to be measure preserving if $\mu(T^{-1}E) = \mu(E)$ for $E \in B$. It is said to be ergodic if $\mu(E) = 0$ or i whenever $T^{-1}E = E$ for $E \in B$. Consider the sequence ${x, Tx, T^2x,...}$ for $x \in X$. One may ask the following questions: What is the relative frequency of the points $T^nx$ which visit the set E\ulcorner Birkhoff Ergodic Theorem states that for an ergodic transformation T the time average $lim_{n \to \infty}(1/N)\sum^{N-1}_{n=0}{f(T^nx)}$ equals for almost every x the space average $(1/\mu(X)) \int_X f(x)d\mu(x)$. In the special case when f is the characteristic function $\chi E$ of a set E and T is ergodic we have the following formula for the frequency of visits of T-iterates to E : $$ lim_{N \to \infty} \frac{$\mid${n : T^n x \in E, 0 \leq n $\mid$}{N} = \mu(E) $$ for almost all $x \in X$ where $$\mid$\cdot$\mid$$ denotes cardinality of a set. For the details, see [8], [10].

• 식물조직배양학회지
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• 제28권4호
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• pp.221-225
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• 2001

사과 갈라 품종의 고효율 형질전환 기술체계를 확립하기 위하여 Agobacterium을 이용한 형질전환에 관여하는 상처유도 방법, 배지 고형물, 엽절편체 기원, acetosyringone의 농도와 MES첨가 등 몇 가지 요인이 재분화 및 형질전환에 미치는 영향에 대하여 연구하였다. 엽절편체의 상처유도는 수술용 핀셋 (non-traumatic forcep)의 사용보다는 단순한 절단 후 균접종과 3일 공동배양을 할 경우 재분화와 형질전환율이 더 증가하는 경향을 나타냈다. Agar (A)와 Gelrit $e^{ }$(G)의 조성에 따른 배지 고형물의 처리에서는 Gelrite의 농도가 높을수록 재분화율이 증가하였으나, 형질전환율에 있어서는 2.5 G, 3.5 A+l.2 G 및 7.0 A의 처리 간에 차이가 없었다. 엽신장배지 또는 증식배지 유래가 재분화 및 형질전환율에 유의한 차이를 보이지는 않았으나, 증식배지 유래가 형질전환율을 더 높이는 경향을 나타냈다. Acetosyringone은 0.1 mM 이상의 농도가 첨가할 경우 높은 재분화 및 형질전환을 나타냈고, 0.15 mM의 농도에서 가장 높은 형질전환율을 나타냈다. MES의 재분화와 형질전환에 미치는 영향은 나타나지 않았다.다.

• Journal of Welding and Joining
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• 제17권6호
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• pp.84-89
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• 1999

Most of ferrous b.c.c weld materials may experience martensitic transformation during rapid cooling after welding. It is well known that volume expansion due to the phase transformation could influence on the relaxation of welding residual stress. To apply this effect practically, it is a prerequisite to establish a numerical model which is able to estimate the effect of phase transformation on residual stress relaxation quantitatively. For this purpose, the analysis is carried out in two regions. i.e., heating and cooling, because the variation of material properties following a phase transformation in cooling is different in comparison with the case in heating, even at the same temperature. The variation of material properties following phase transformation is considered by the adjustment of specific heat and thermal expansion coefficient, and the distribution of residual stress in analysis is compared with that of experiment by previous study. consequently, in this study, simplified numerical procedures considering phase transformation, which based on a commercial finite element package was established through comparing with the experimental data of residual stress distribution by other researcher. To consider the phase transformation effect on residual stress relaxation, the transition of mechanical and thermal property such as thermal expansion coefficient and specific heat capacity was found by try and error method in this analysis.

• Journal of Microbiology and Biotechnology
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• 제20권6호
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• pp.1022-1026
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• 2010

The different cleavage patterns of pYBamy59 plasmid isolated from E. coli $DH5{\alpha}$ and B. longum MG1 by the cell extract of B. longum MG1 suggested that the main reason for its low transformation efficiency was related to the restriction modification (R-M) system. To confirm the correlation between the R-M system and transformation efficiency, in vitro methylation and site-directed mutagenesis were performed in pYBamy59. Sequence analysis of pYBamy59 fragments digested by the cell extract of B. longum MG1 revealed that all fragments were generated by restriction of the sequence recognized by SacII endonuclease. When pYBamy59 from E. coli was methylated in vitro by CpG or GpC methyltransferase, it was protected from SacII digestion. Site-directed mutagenesis, which removed SacII sites from pYBamy59, or in vitro methylation of pYBamy59 showed 8- to 15-fold increases in the transformation efficiency over intact pYBamy59. Modification of the SacII-related R-M system in B. longum MG1 and in vitro methylation in pYBamy 59 can improve the transformation efficiency in this strain. The results showed that the R-M system is a factor to limit introduction of exogenous DNA, and in vitro modification is a convenient method to overcome the barrier of the R-M system for transformation.

• Journal of Plant Biotechnology
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• 제48권4호
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• pp.246-254
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• 2021

Environmental stresses are estimated to have reduced global crop yields of wheat by 5.5%. However, traditional approaches for the transfer of resistance to these stresses in wheat plants have yielded limited results. In this regard, genetic transformation has undoubtedly opened up new avenues to overcome crop losses due to various abiotic stresses. Particle bombardment has been successfully employed for obtaining transgenic wheat. However, most of these procedures employ immature embryos, which are not available throughout the year. Therefore, the present investigation utilized mature seeds as the starting material and used the calli raised from three Moroccan durum wheat varieties as the target tissue for genetic transformation by the biolistic approach. The pANIC-5E plasmid containing the SINA gene for drought and salinity tolerance was used for genetic transformation. To enhance the regeneration capacity and transformation efficiency of the tested genotypes, the study compared the effect of copper supplementation in the induction medium (up to 5 μM) with the standard MS medium. The results show that the genotypes displayed different sensitivities to CuSO₄, indicating that the transformation efficiency was highly genotype-dependent. The integration of transgenes in the T₀ transformants was demonstrated by polymerase chain reaction (PCR) analysis of the obtained resistant plantlets with primers specific to the SINA gene. Among the three genotypes studied, 'Isly' showed the highest efficiency of 9.75%, followed by 'Amria' with 1.25% and 'Chaoui' with 1%.

• 원자력산업
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• 제21권4호통권218호
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• pp.38-49
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• 2001

• 한국유통학회:학술대회논문집
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• 한국유통학회 2002년도 심포지움
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• pp.1-16
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• 2002