• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.393-397
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• 1999

The gene (galE) encoding UDP-galactose-4-epimerase, operative in the galactose metabolic pathway, was cloned together with the $\beta$-galactosidase gene (lacZ) from Lactococcus lactis ssp. lactis ATCC7962 (L. lactis 7962). galE was found to have a length of 981 bps and encoded a protein with a molecular mass of 36,209 Da. The deduced amino acid sequence showed a homology with GalE proteins from several other microorganisms. A Northern analysis demonstrated that galE was constitutively expressed by its own promoter. When galactose or lactose was added into medium, the galE transcription was induced by several upstream promoters. The structure of the gal/lac operon of L. lactis 7962 was partially characterized and the gene order around galE was galT-lacA-lacZ-galE-orfX.

• 제어로봇시스템학회논문지
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• 제18권10호
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• pp.940-946
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• 2012

This paper proposes a method to predict maximum traction for unmanned robots on rough terrain in order to improve traversability. For a traction prediction, we use a friction-slip model based on modified Brixius model derived empirically in terramechanics which is a function of mobility number $B_n$ and slip ratio S. A friction-slip model includes characteristics of various rough terrains where robots are operated such as soil, sandy soil and grass-covered soil. Using a friction-slip model, we build a prediction model for terrain parameters on which we can know maximum static friction and optimal slip with respect to mobility number $B_n$. In this paper, Mobility number $B_n$ is estimated by modified Willoughby Sinkage model which is a function of sinkage z and slip ratio S. Therefore, if sinkage z and slip ratio are measured once by sensors such as a laser sensor and a velocity sensor, then mobility number $B_n$ is estimated and maximum traction is predicted through a prediction model for terrain parameters. Estimation results for maximum traction are shown on simulation using MATLAB. Prediction Performance for maximum traction of various terrains is evaluated as high accuracy by analyzing estimation errors.

• Journal of Ecology and Environment
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• 제29권1호
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• pp.29-34
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• 2006

Three macrophytes species, that are, Phragmites australis, Zizania latifolia and Typha angustifolia were grown in mono culture in order to compare growth (relative biomass increase rate), variation of photosynthetic pigment (total chlorophyll, Chl a, Chl b and Chl a/Chl b) and effectiveness of nutriment removal in 15%o NaCl-salt solution or processed-leachate (salinity 19.6%o) from sanitary landfill sites. The relative biomass increase rate of p. australis was significantly higher than Z. latifolia and T. angustifolia. In the case of processed-leachate treatment, the relative biomass increase rates of above-part, rhizome and root of P. australiswere 178 %, 148 % and 157 %, respectively. Also, in 15%o NaCl-salt solution treatment, the relative biomass increase rates of P. australis increased as follows; 161 % (above-part), 183 % (rhizome) and 112 % (root). Total chlorophyll contents increased significantly in the leaves of P. australis and Z. latifolia grown in 15%o NaCl-salt solution and processed-leachate. Among three macrophytes, P. australis was evaluated as most effective macrophyte for the biological retreatment of processed-leachate from sanitary landfill sites.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권11호
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• pp.717-723
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• 1999

The transient characteristics of grounding systems play a major role in the protection of power equipments, electronic circuits and info-communication facilities against surges which arise from lightning or ground faults. Electronic devices are very weak against lightning surges injected from grounding systems and can be damaged. The malfunction and damage of electronic circuits bring about bad operation performances, a lot of economical losses, and etc. Therefore, in order to obtain the effective protection measure of electronic devices from overvoltages and lightning surges, the analysis of the transient grounding impedances in essential. One of this work is to examine the transient behaviors of grounding impedances under steplike currents for various grounding systems. And the other of this work is to evaluate the transient behaviors of a grid with rods under impulse currents and to investigate the effect of grounding lead wire. Transient grounding impedances of a grid with rods under impulse current waves have been measured as a parameter of the length of the grounding leads. Z-t, Z-i and V-i curves of transient grounding impedance under impulse current waveforms have been measured and analyzed. It was found that the grounding impedance gives the inductive, resistive and capacitive aspects under steplike current. Transient grounding impedance characteristics were very different with shapes, geometries of ground electrodes. Also, they were dependent on the waveform and magnitude of impulse current.

• 전력전자학회논문지
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• 제19권3호
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• pp.201-210
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• 2014

In this paper, dc-link voltage control of a grid-connected QZSI is presented. Since the input current of the ZSI is discontinuous, a capacity with relatively large capacitance should be connected to the output of the PV array in order to reduce the current ripple. Due to the presence of the impedance network inductor in series with the PV array, the QZSI can achieve continuous input current flow. Several dc-link voltage control methods are compared and the method for power quality improvement is also presented. The performance of the proposed method is verified through both simulation and experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1377-1379
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• 1996

In this paper, each parameter was identified by the gradient descent method to overcome difficulty deciding fuzzy rules of FLC for the unknown process and the type of membership Junctions. Usually PID or optimal control theories have been mostly usee in control field so far. However, optimal control requires much time for calculation because of adaptation for disturbance and nonlinearity. And intricate technique such as MRAS which can be realized only by an expert are limited to be used in the systems requiring rapid and precise response because of comparatively longer calculating time and complicateness. Gradient descent method is a method to find Z minimizing a function about a certain vector Z. And required output of FLC is gained using gradient approaching method in order to adapt control rule parameters of FLC. Simulation proved validation of this algorithm.

• Nuclear Engineering and Technology
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• 제31권5호
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• pp.512-521
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• 1999

A feasibility study was performed to design an epithermal neutron beam for BNCT using the neutron of 2.45 MeV on the average produced from $^2H(d,n)^3$He reaction induced by plasma focus in the z-pinch instead of the conventional accelerator-based $^3H(d, n)^4$He neutron generator. Flux and spectrum were analyzed to use these neutrons as the neutron source for BNCT. Neutronic characteristics of several candidate materials in this neutron source were investigated Using MCNP Code, and $^7LiF$ ; 40%Al + 60%$AIF_3$, and Pb Were determined as moderator, filter, and reflector in an epithermal neutron beam design for BNCT, respectively. The skin-skull-brain ellipsoidal phantom, which consists of homogeneous regions of skin-, bone-, or brain-equivalent material, was used in order to assess the dosimetric effect in brain. An epithermal neutron beam design for BNCT was proposed by the repeated work with MCNP runs, and the dosimetric properties (AD, AR, ADDR, and Dose Components) calculated within the phantom showed that the neutron beam designed in this work is effective in tumor therapy. If the neutron source flux is high enough using the z-pinch plasma, BNCT using the neutron source produced from $^2H(d,n)^3$He reaction will be very feasible.

• 한국소음진동공학회논문집
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• 제14권7호
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• pp.632-638
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• 2004

In order to evaluate the effect of blasting vibration in buildings and it's resident located around blasting construction field in urban area, blasting vibration characteristics were measured by the vibration level, vibration velocity. The 250g and 750g of charged powder were used at the apartment and at the ground, respectively. In the measurement of the ground, 2 (perpendicularity) axis was the highest value in vibration level, but vertical direction was the highest value at 25 m point and longitudinal direction was the highest value at 50 m point in vibration velocity. The amount of measurement was high value when measuring point is higher than blasting source, while that of measurement was low value when measuring point is lower than blasting source. In the measurement of the apartment, Z axis was the highest value in vibration level, but in vibration velocity transverse direction was the highest value at ground, was vertical direction at 1st floor, was longitudinal direction at 3rd floor and was vertical and longitudinal direction at 5th floor. The vibration level and the vibration velocity of 50 m point showed higher correlation value than 25 m point at the ground, but those of 25 m point showed higher correlation value than 50 m point at the apartment.

• 수산해양기술연구
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• 제31권2호
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• pp.166-171
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• 1995

전자자기 컴퍼스의 바위 검출용소자로서, 3축 자기검출소자를 사용한 방위산출의 방법과 자동적인 자차수정의 가능성을 확인하기 위하여 디비에스코프를 이용한 자차측정 시뮬레이션을 한 결과, 3축 자기검출소자로 측정되는 선내자계로부터, 선체 유도자기계수와 영구자기성분의 크기인 포와숀 계수의 산출이 가능한 뿐 아니라 이들 계수는 자기위도의 변화에 관계없이 항상 일정한 값을 갖고 있기 때문에 어느 지점에 있어서의 지자기의 성분(X, Y, Z)의 값을 대입한다고 하면 3축 자기 센서로 측정되는 선내 자계(X', Y', Z')의 측정치로부터 선수자기방위의 산출이 가능하며, 또한 산출된 포와숀 계수로부터 자차 및 자차계수가 구해지기 때문에 이들 계수를 이용한 소프트웨어적인 계산방법으로 자동적인 자차수정의 가능성을 확인 할 수 있었다.

• Archives of Pharmacal Research
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• 제25권4호
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• pp.469-474
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• 2002

The inner shell of the chestnut (Castanea crenata S. et Z., Fagaceae) has been used as an anti-wrinkle/skin firming agent in East Asia, and preliminary experiments have found that a 70% ethanol extract from this plant material can prevent cell detachment of skin fibroblasts from culture plates. In order to examine the molecular mechanisms underlying this phenomenon, its effects on the expression of adhesion molecules, such as fibronectin and vitronectin, were investigated using the mouse skin fibroblast cell line, NIH/3T3. Using fixed-cell ELISA, Western blotting and immunofluorescence cell staining, it was clearly demonstrated that the chestnut inner shell extract enhanced the expression of the cell-associated fibronectin and vitronectin. Scoparone (6,7-dimethoxycoumarin), isolated from the extract, also possessed similar properties. These findings suggest that the enhanced expression of the adhesion molecules may be one of the molecular mechanisms for how the chestnut inner shell extract preventing cell detachment and may be also responsible for its anti-wrinkle/skin firming effect.