• Journal of Microbiology and Biotechnology
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• 제21권10호
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• pp.1049-1052
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• 2011

In this study, we demonstrated the asymmetric synthesis of L-tert-leucine from trimethylpyruvate using branched-chain aminotransferase (BCAT) from Escherichia coli in the presence of L-glutamate as an amino donor. Since BCAT was severely inhibited by 2-ketoglutarate, in order to overcome this here, we developed a BCAT/aspartate aminotransferase (AspAT) and BCAT/AspAT/pyruvate decarboxylase (PDC) coupling reaction. In the BCAT/AspAT/PDC coupling reaction, 89.2 mM L-tert-leucine (ee>99%) was asymmetrically synthesized from 100 mM trimethylpyruvate.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.162-165
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• 2006

I-section prestressed concrete(I-PC) beam crack due to low tensile strength, may decrease rigidity and structural performance by excessive deflection. In an effort to this problem, in this research, I-section prestressed dual concrete(I-PDC) beam has been proposed, consisting of normal strength concrete in compression zone, and high performance steel fiber reinforced concrete(HPSFRC) with a bottom flange depth in tensile zone. Crack formation and its propagation are controlled by the HPSFRC in I-PDC beam. The initial cracking and service limit loads are increased along with the load carrying capacity and flexural stiffness.

• 한국지능시스템학회논문지
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• 제11권8호
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• pp.771-775
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• 2001

본 논문에서는 유도탄 오토파일롯을 제어하기 위해 T-S 퍼지 모델링을 한 다음 병렬분상이론을 적용하여 적응 퍼지 제어기를 설계한다. 추가적으로 제어기의 파라미터는 기준모델과 출력간의 에러, 스테이트, 기준입력 신호를 이용하여 실시간 업데이트되며, 원 플랜트에 대해 regulation 제어가 성공적으로 해결함을 미사일 모델에 적용한 모의 실험 결과로부터 보인다.

• 제어로봇시스템학회논문지
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• 제8권11호
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• pp.916-921
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• 2002

We presents a new method of constructing an equivalent T-S fuzzy model by using the sum of products of linearly independent scalar functions from nonlinear dynamics. This method exactly expresses nonlinear systems and automatically determines the number of rules. We design a stabilizing controller f3r ul inverted pendulum system by using the concep of parallel distributed compensation (PDC) and linear matrix inequalities (LMIs) based on the proposed T-S fuzzy modeling method. We show effectiveness of a systematically designed fuzzy controller based on the proposed T-S fuzzy modeling method through the simulation and experiment of an inverted pendulum system.

• 소성∙가공
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• 제31권6호
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• pp.337-343
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• 2022

Electrically assisted pressure joining (EAPJ) utilizes electric current-induced kinetic enhancement to achieve solid state diffusion bonding within a short time. In this study, aluminum alloy specimens, which are known as a hard-to-weld metal, were successfully solid-state joined through EAPJ. The bonding process was performed in two ways: continuous direct current (CDC), which applies relatively low current density, and pulsed direct current (PDC), which applies high current density. It was observed that the bonding strength was higher in PDC than in CDC. The microstructure of the joint was characterized using 3D X-ray microscopy (XRM) and electron backscatter diffraction (EBSD).

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.2917-2924
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• 2012

Four novel metal-organic complexes $[Cd_2(IP)_2(TBZ)_2(H_2O)_2]{\cdot}(H_2O)$ (1), $[Zn_4(IP)_4(TBZ)_4]{\cdot}2(H_2O)$ (2), $[Zn_2(BTC)(TBZ)_2(CO_2H)]$ (3), [Co(PDC)(TBZ)] (4) (where IP = isophthalate; TBZ = thiabendazole; BTC = 1,3,5-benzenetricarboxylate; PDC = pyridine-3,4-dicarboxylate) have been prepared and characterized by IR spectrum, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. X-ray structure analysis reveals that 1, 2, and 3 are one-dimensional chain polymers, while 4 is a two-dimensional network polymer. The TBZ acts as a typical chelating ligand coordinated to the metal center in all complexes. The 1D chain architecture of 1 is constructed from isophthalates and cadmium atoms. A simultaneous presence of chelating, monodentate and bidentate coordination modes of IP ligands is observed in complex 2. In complex 3, the 16-membered rings are alternately arranged forming an infinite 1D double-chain structure. The 2D skeleton of 4 is formed by cobalt ions as nodes and PDC dianions as spacers, through coordination bonds. The hydrogen bonds and ${\pi}-{\pi}$ stacking play important roles in affecting the final structure where complexes 1 and 3 have 2D supramolecular networks, while complexes 2 and 4 have 3D supramolecular architectures.

• 한국작물학회지
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• 제54권4호
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• pp.390-396
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• 2009

인삼 논재배 안전생산기술을 개발하기 위해 배수불량지와 배수약간불량지 논토양에서 청3+흑1중직 차광망, 청색차광지 및 은박차광판 해가림을 처리하여 3년생 천풍의 생육특성 및 진세노사이드 함량을 조사한 결과는 다음과 같다. 해가림 유형별 투광량과 기온은 차광지 > 은박차광판 > 차광망 순이었다. 배수불량지의 토양수분장력은 평균 64mbar (절대토양수분함량 25%)로 과습한 조건이었으며, 배수약간불량지에서는 평균 123 mbar (절대수분함량 17%)이었다. 배수불량지의 토양수분장력은 계절과 해가림 유형별 뚜렷한 차이를 보이지 않았지만 배수약간불량지에서는 60~200 mbar의 범위에서 계절적 변화를 보였으며, 해가림유형에 따라 약간의 차이를 보였다. 배수불량지의 수량성은 황증과 적변 발생율의 증가로 배수약간불량지보다 현저히 감소되었다. 해가림 유형별 수량성은 배수불량지에서 차광지가, 배수약간불량지에서 차광망이 가장 높았다. 적변 발생율은 배수등급과 해가림 유형에 따라 일정한 경향이 없었다. 배수불량지는 Panaxatriol 계열 (Rg1, Re 및 Rf)의 진세노사이드 함량이 감소되고 Panaxadiol 계열 (Rb1, Rc 및 Rd)의 함량이 증가되었다. 총 진세노사이드 함량은 배수불량지보다 배수약간불량지에서 높았으며, 해가림 유형별 총 진세노사이드 함량은 배수등급에 관계없이 차광지에서 가장 높았다.

• 한국약용작물학회지
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• 제17권5호
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• pp.346-351
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• 2009

To study the optimal cultivation for paddy soil, growth characteristics and ginsenoside content was investigated by both of poor drainage class (PDC) and imperfect drainage class (IDC) in three-year-old ginseng of varieties, Cheonpoong (CP), Yeonpoong (YP), Hwangsookjong (HS), and Jakyeongjong (JK). Root yield of IDC was higher than that of PDC by 3.6 times because stem length, leaf area, and chlorophyll contents were increased, while discolored leaf ratio was decreased. Root yield of HS in PDC was highest among four varieties because chlorophyll contents, leaf area, and survived plant ratio were relatively high. Root yield of CP in IDC was highest among four varieties because of high leaf area and survived plant ratio, and low discolored leaf ratio. Ratio of rusty-colored root showed significant difference by varieties, which was the highest in HS and the lowest in CP among four varieties irrespective of drainage classes. Total ginsenoside contents showed significant difference by drainage classes, which were high in IDC of good growth and low in PDC of poor growth. Total ginsenoside contents were high in JK and CP, while low in HS and YP both of drainage classes.

• Asian-Australasian Journal of Animal Sciences
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• 제19권3호
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• pp.347-355
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• 2006

A study was conducted to predict the rumen microbial protein production based on urinary excretion of purine derivatives in buffaloes fed a diet of wheat straw and concentrate (40:60) at four fixed levels of feed intake. (95, 80, 60 and 40% of preliminary voluntary feed intake) following experimental protocol of IAEA (Phase I). The buffaloes were allocated according to a $4{\times}4$ latin square design. The urinary allantoin, uric acid, total PD excretion (mmol/d) in treatments L-95, L-80, L-60 and L-40 was 20.13, 16.00, 12.96 and 9.17; 1.88, 2.12, 2.11 and 2.15; 22.01, 18.12, 15.07 and 11.32, respectively and were significantly (p<0.05) different among treatments except for uric acid. The rate of PD excretion (mmol/d) was positively correlated with the digestible organic matter intake. Variations were observed in PD and creatinine concentration in spot samples collected at 6-hour interval. However, daily PD:Creatinine ratio (PDC index) appears to be a reasonably good predictor of microbial-N supply. The contribution of basal purine excretion to total excretion of purine derivatives (PD) was determined in pre-fasting period followed by a fasting period of 6 d (Phase II). Daily PD and creatinine excretion (mmol/kg $W^{0.75}$) during fasting averaged 0.117 and 0.456 respectively for buffaloes. The excretion rates of PD decreased significantly (p<0.01) during fasting compare to pre-fasting period, the urinary creatinine excretion remained almost similar. Except for creatinine, plasma concentration of target parameters significantly (p<0.01) declined during fasting. Likewise, glomerular filtration rate (GFR) and renal clearance of allantoin and uric acid also decreased. Based on the PD excretion rates during fasting and at different levels of feed intake obtained in this study, a relationship between daily urinary PD excretion (Y-mmol) and microbial purine absorption (X-mmol) was developed for buffaloes as Y = 0.74X+0.117 kg $W^{0.75}$. The microbial N supply (g/kg DOMI) remained statistically similar irrespective of dietary treatment. The results showed that excretion of urinary purine derivatives is positively correlated with the levels of feed intake in Murrah buffaloes and thus, estimation of urinary purine derivatives and PDC index could be used to determine microbial nitrogen supply when there is large variation in level of feed intake.

• 대한토목학회논문집
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• 제30권1C호
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• pp.45-51
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• 2010

지하철 터널 시공, 지하공간 시공, 대심도 굴착 등과 같이 도심지에서의 토목구조물 설계와 시공에 있어서 큰 어려움 중의 하나는 도심지 지반조사이다. 여러 가지 지장물, 전기 잡음, 교통 진동 등과 같은 자연적, 인위적 장애물로 인하여 어느 지반조사 기법이든지 그 결과의 신뢰성은 그리 높지 않은 상황이다. 본 연구에서는 이와 같이 현실적 요구가 높은 고품질 도심지 지반조사 기법의 개발을 목표로 하여 선행연구를 수행하였고, 일차적으로 HiRAS(Hybrid Integration of Resistivity and Surface Wave Velocities) 라고 하는 표면파-전기비저항 병합기법을 개발하였다. HiRAS 기법은 표면파 기법인 CapSASW 기법과 전기비저항 기법인 PDC-R 기법을 병합한 것으로서, 지반 매질의 강성 평가에 우수한 CapSASW 기법의 장점과, 전기잡음에 대한 내성과 지층변화 평가에 우수한 특성을 가진 PDC-R 기법의 장점을 동시에 활용하고자 한 것이다. 표면파 기법과 전기비저항 기법을 동시에 활용하는 역산해석의 측면에서는 표면파 기법의 탄성파 속도와 전기비저항 시험의 전기비저항 간의 부지고유관계를 이용하여 병합역산을 수행하는 전략을 채택하였다. 또한 HiRAS 기법 개발과정에서 부차적으로 지반매질의 포아송비 분포를 2차원으로 평가할 수 있는 성과도 도출하였다.