• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2011년도 춘계학술발표회
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• pp.462-463
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• 2011

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2010년도 심포지엄 및 추계학술발표회
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• pp.491-492
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• 2010

• 열처리공학회지
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• 제12권2호
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• pp.145-156
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• 1999

The distribution of the second phase, the change of transformation temperature and mechanical properties with thermomechanical treatment conditions were investigated by metallography, calorimetry, EDS, tensile test and fractography in a Cu-Al-Ni-Ti-Mn alloy. The cast structure revealed Ti-rich precipitates($X_L$ phase) between dendrite arms, which have been identified as $(Cu,Ni)_2TiAl$ intermetallic compounds. By homogenizing above $900^{\circ}C$, the $X_L$ phase was melted in the matrix, while the Xs phase was precipitated in matrix and the volume fraction of it was increased. When hot-rolled specimen was betatized below $750^{\circ}C$, recrystallization could not be observed. However, the specimen betatized above $800^{\circ}C$ was recrystallized and the grain size was about $50{\mu}m$, while Xs phase was precipitated in matrix. With raising betatizing temperature, $M_s$ and $A_s$ temperatures were fallen and transformation hysteresis became larger. The strain of the specimen betatized at $800^{\circ}C$ was 8.2% as maximum value. The maximum shape recovery rate could be obtained in the specimen betatized at $800^{\circ}C$ but it was decreased due to the presence of Xs phase with increasing betatizing temperature.

• Natural Product Sciences
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• 제22권3호
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• pp.216-219
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• 2016

The microbial transformation of anthranilic acid (1) by the marine-mudflat-derived fungus Thielavia sp. produced an antibacterial polycyclic quinazoline alkaloid, thielaviazoline (2). The stereostructure of the metabolite was assigned based on detailed spectroscopic data analyses including comparison of the NMR ($^1H$ and $^{13}C$) data with those of reported compound (2). Compound 2 displayed in vitro antimicrobial activity against methicillin-resistant and multidrug-resistant Staphylococcus aureus (MRSA and MDRSA), with minimum inhibitory concentrations (MICs) of 6.25 and $12.5{\mu}g/mL$, respectively. Compound 2 also showed potent radical-scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) with an $IC_{50}$ of $11{\mu}M$, which was more active than the positive control, L-ascorbic acid ($IC_{50}$, $20.0{\mu}M$).

• 한국전산구조공학회논문집
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• 제27권4호
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• pp.265-271
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• 2014

304L 스테인리스강판은 멤브레인타입 LNG선 단열시스템의 1차 방벽으로 이용된다. 304L 스테인리스강은 변태유기소성(TRIP)강으로 복잡한 재료거동을 보이는데, 이는 소성변형이 발생하는 동안 상변태를 경험하기 때문이다. 본 연구에서는 304L 스테인리스 강의 비선형 기계적 거동분석을 위한 온도의존 일축인장시험을 수행하였으며 재료의 파단이나 비선형 거동을 예측하기 위한 점소성모델을 제안하였다. 수치해석의 결과와 시험 결과를 비교 분석하여 유효성을 검증하였으며 LNG 멤브레인에 대한 적용성을 검토하기 멤브레인 구조시편을 제작하여 구조해석 및 유한요소해석을 수행하였다. 재료모델은 개발 서브루틴을 이용하였으며 ABAQUS 사용자지정 재료 서브루틴을 탑재한 유한요소해석 결과와 극저온 구조인장시험을 수행한 결과를 비교하여 구조적용성을 검증하였다.

• 한국초지조사료학회지
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• 제26권2호
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• pp.77-82
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• 2006

유용유전자 도입을 통한 신품종 톨 페스큐를 개발할 목적으로 Agrobacterium을 이용한 효율적인 식물체 재분화 및 형질전환에 미치는 몇 가지 요인을 조사하였다. 성숙종자로부터 유도된 캘러스를 형태에 따라 3가지 type으로 분류하였고 type II 캘러스는 유백색으로 녹색을 띠며 조직적으로 치밀한 상태이며 식물체로의 재분화효율이 52.6%로 가장 높게 나타났다. 또한 재분화 배지에 $AgNO_3$와 cysteine을 동시에 첨가해 준 경우 무첨가구에 비해 캘러스 유도율은 6.7%, 식물체 재분화율은 12% 씩 각각 증가하였다. 캘러스 type 별 형질전환 효율을 조사한 결과 type II 캘러스는 58.0%로 가장 높은 형질전환효율을 나타내었다. 형질전환체를 PCR 및 PCR-Southern blot 분석을 실시하여 본 결과 발현벡터의 T-DNA 영역이 형질전환 식물체의 genome에 성공적으로 도입되었음을 확인할 수 있었다. 본 연구를 통하여 확립된 효율적인 형질전환 시스템은 분자육종을 통한 신품종 톨페스큐의 개발에 유용하게 이용될 수 있을 것이다.

• Communications for Statistical Applications and Methods
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• 제15권5호
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• pp.775-781
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• 2008

It is developed that a family of the semicircular Laplace distributions for modeling semicircular data by simple projection method. Mathematically it is simple to simulate observations from a semicircular Laplace distribution. We extend it to the l-axial Laplace distribution by a simple transformation for modeling any arc of arbitrary length. Similarly we develop the l-axial log-Laplace distribution based on the log-Laplace distribution. A bivariate version of l-axial Laplace distribution is also developed.

• 전력전자학회논문지
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• 제25권1호
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• pp.54-60
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• 2020

A digital current control scheme using virtual d-q transformation for a boost single-phase power factor correction (PFC) converter is proposed. The use of virtual d-q transformation in single-phase power converters is known to improve current control performance. However, the conventional virtual d-q transformation-based digital current control scheme cannot be directly applied to the boost single-phase PFC converter because the current and average voltage waveforms of the inductor used in the converter are not sinusoidal. To cope with this problem, this study proposes a virtual sinusoidal signal generation method that converts the current and average voltage waveform of the inductor into a sinusoidal waveform synchronized with the grid. Simulation and experimental results are provided to show that the virtual d-q transformation-based digital current control is successfully applied to the boost single-phase PFC converter with the aid of the proposed virtual sinusoidal signal generation method.

• Journal of Plant Biotechnology
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• 제30권2호
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• pp.115-121
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• 2003

In this study, plant regeneration and Agrobacterium tumefaciens-mediated transformation Kentucky bluegrass(Poa pratensis L.) were evaluated. Three different types of calli were produced depending on the combinations of growth regulators. They were non-friable brown or gray-colored callus (type I), compact, friable and yellow or white-colored callus (typeII), and soft, watery translucent callus with differentiated structure (typeIII). The highest regenerable organogenic callus (typeII) was obtained on the medium containing 1mg/L, 2,4-D and 0.1mg/L BA. Additionally, the production of typeII calli increased significantly when AgNO$_3$ was added to the callus induction and growth medium. The highest frequency of multiple shout formation from typeII callus was obtained on MS medium containing 1mg/L BA and 1mg/L Thidiazuron(TDZ). The organogenic calli(typeII) were inoculated with Agrobacterium tumefaciens strain EHA101 harboring the binary vector pIG121Hm with $\beta$-glucuronidase gene, and various factors were found to influence the transfer-DNA delivery efficiency. The highest transient GUS activity was observed on typeIIcallus. In the present work, we reported the first transient GUS activity of Kentucky bluegrass mediated by Agrobacterium tumefaciens. Our system may contribute to genetic improvement for breed-recalcirtrant grass species, Kentucky bluegrass.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.294-301
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• 2001

The effects of including glycine and isonicotinic acid hydrazide (INH) in the growth medium (Luria broth, LBG) on the subsequent lysozyme-imduced protoplast formation and transformation efficiency of Corynebacterium glutamicum were studied. The transformation efficiency of C. glutamicum AS019 increased up to 100-fold as the ocncentrationof glycine in the media increased from 0% to 5% (w/v), relative to cells grown in the absence of glycine. The presence of 5 mg/ml INH in the growth medium led to a further 10-fold increase in transformation efficiency. In addition, this transformation protocol was successfully applied to other strains of C. glutamicum. Both chemicals affected the mycolic acid attachment to the cell surface of C. glutamicum, when INH, the relative percentage of fatty acids of AS019 to the total lipids (mycolic acid plus fatty acids) decreased from 76.9% (in LBG) to 72.9% (in LBG-2% glycine) and 66.4% (in LBG-8 mg InG/ml), thereby suggeting that these chemicals also inhibit fatty acid synthesis.