• Journal of Microbiology
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• 제38권4호
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• pp.245-249
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• 2000

Catabolic pathways for the degradation of various aromatics by Sphingomonas yanoikuyae Bl are intertwined, joining at the level of substituted benzoates, which are further degraded vita ring cleavage reactions. The mutant strain EK497, which was constructed by deleting a large DNA region containing most of the genes for biphenyl, naphthalene, m-xylene, and m-toluate degradation, was unable to grow on all of the aromatics tested except for benzoate as the sole source of carbon and energy.S. yanoikuyae EK497 was found to possess only catechol ortho-ring cleavage activity due to deletion of the genes for the meta-cleavage pathway. Wild-type S. yanoikuyae Bl grown on benzoate has both catechol orthoand meta-cleavage activity. However, m-xylene and m-toluate, which are metabolized through methylbenzoate, and biphenyl, which is metabolized through benzoate, induce only the meta-cleavage pathway, suggesting the presence of a substrate-dependent induction mechanism.

• Clinical and Experimental Pediatrics
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• 제52권6호
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• pp.696-700
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• 2009

목 적 : Artemisinin은 인체에 대한 부작용이 적고 항말라리아 효능 뿐 아니라 강력한 항암효과가 있음이 알려져 있다. 저자들은 오까야마 약학대학에서 합성 된 350여개의 endoperoxide ring구조를 가진 artemisinin 유도체를 선별검사 하여 HL-60세포 주에 강력한 세포독성을 보여 준 c-127의 세포고사 유도 여부와 그 분자유전학적 기전을 알아보고자 하였다. 방 법 : HL-60세포는 RPMI 1640배지로 배양하였고 세포 생존율은 MTT분석으로 측정하였다. 세포고사 여부는 DNA추출과 전기영동법으로 확인하였으며 세포고사 유도 기전은 western blotting을 시행하여 알아보았다. 결 과 : C-127이 세포고사를 유도하여 HL-60세포의 세포 생존력을 농도 의존적으로 감소시켰다. C-127의 이런 항암효과의 분자 유전학적 기전으로는 caspase-8,3 활성화, Bcl-2 family인 Bid분절, JNK 인산화와 c-Jun 발현이 관여하였다. 결 론 : C-127이 HL-60 세포에서 세포고사를 유도하여 강력한 항암효과를 발현하였고, 그 기전으로 caspase cascade, Bcl-2 family, JNK인산화와 c-Jun활성화가 관여하였다.

• 전기의세계
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• 제22권3호
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• pp.25-34
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• 1973

In this paper, the characteristics of a single phase induction motor which is considered the space harmonic flux by the double revolving field theory is analysed. As the rotor resistance for the fundamental flux is separated from the resistance for the rotor bar and end-ring, and the rotor leakage reactnace is separated from the skew leakage reactance and the other, so the circuit constants for the space harmonic flux is expressed by the circuit constants for the fundamentals. As the ratio of the circuit constants for the magnetizing reactance is used, the generalized equivalent circuit is made up. the characteristic equation which is able to analysis the subdivided characteristics by the above circuit is induced. The ratio of the circuit constants and the skew angle being changed, the variations of the torque-speed characteristics for the fundamentals and harmonics is examined by this equation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2175-2177
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• 2001

This paper presents a faults diagnosis technique of induction motors based on a neural network. Only stator current is measured, transformed by using FFT and normalized for the training. Healthy, bearing fault, stator fault and rotor end-ring fault motors are prepared to obtain the learning data and diagnose the several faults. For more effective diagnosis, the load rate is changed by 100%, 60%, 30% of full load and the obtained are applied to the learning process. The experimental results show the proposed method is very detectable and applicable to the real diagnosis system.

• 한국정보통신학회논문지
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• 제6권2호
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• pp.294-299
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• 2002

이 논문은 신경회로망을 기반으로 한 유도전동기의 고장 진단 기법을 제시한다. 제안된 기법은 고정자전류만을 측정하여 FFT 변환 후 진단 훈련을 위해 일반화한다. 정상, 베어링고장, 고정자 권선고장 그리고 회전자 엔드-링 고장을 갖는 모터로부터 학습데이터를 획득하고 여러 고장 유형을 진단한다. 더욱 효과적인 고장 진단을 위해, 전부하의 100％, 60％, 30％로 부하율을 변화시켜서 학습절차에 적용하였다. 실험 결과들은 제안된 방법이 오차 범위 0.56％∼0.04％와 같은 높은 진단 정밀도를 가지고 있어 실제 진단시스템에 적용 가능함을 보여주고 있다.

• 전기의세계
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• 제19권2호
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• pp.6-11
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• 1970

For the variable speed in automatic control, this paper describes, at first, performance equations of an induction motor which has the free rotating stator. This motor with rotating stator has a speed control factor itself by equivalent variable frequency in stator side. Secondly, an additional invertor source on the rotor slip ring serves the purpose of improving the speed control factor. The advantages decribed above permit to control the speed continuosly from zero to maximum allowable speed with low energy of thyristor a feed-back device may be used for speed stabilization under variable load.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2002년도 춘계학술대회논문집
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• pp.141-146
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• 2002

The cast iron cylinder liner of the marine engine must be scrapped after its inner surface was definitely worn out due to the friction between the surface and piston ring during the operating. In this research, the restoring method of the worn out cast iron cylinder liner are discussed based on the results of experimental work of the thermal plastic deformation technique.

• 대한금속재료학회지
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• 제49권1호
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• pp.85-91
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• 2011

Alnico magnets can be used as magnetic bearings for the precise electric power measuring instruments such as watt-hour meters because they have high remanence ($B_r$), relatively high maximum energy product ($(BH)_{max}$), and excellent temperature stability. In this study, Alnico composite magnets were fabricated by appropriately mixing alnico alloy powders with epoxy resin and binder. The Alnico powders mixed with epoxy resin and a hardening agent with a mixing ratio of 96:4 were pressed and then cured to be a toroid-type ring magnet with an outer diameter (${\Phi}_{out}$) of 15 mm, an inner diameter (${\Phi}_{in}$) of 6.5 mm and a thickness (t) of 2.5 mm, respectively. The magnetic properties of the Alnico ring magnets were varied with the mixing ratio of Alnico powders that possess different average particle sizes. The Alnico ring magnet prepared by mixing 5 wt% of $50{\mu}m$ (small size) powder, 15~20 wt% of $150{\mu}m$ (medium size) powder, and 75~80 wt% of $300{\mu}m$ (large size) powder showed the best magnetic properties (remanent induction, coercive force, maximum energy product, and surface flux density). In addition, measurements of temperature and moisture characteristics for the Alnico ring magnets showed that the surface flux densities of the N and S poles decreased little and the repulsive distance between the magnets decreased as small as 0.05 mm after 10 days.

• Environmental Analysis Health and Toxicology
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• 제13권3_4호
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• pp.55-61
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• 1998

Glutathione-S-transferases (GSTs) detoxify electrophilic xenobiotics and reactive metabolites. Recently benzene-fused heterocycles have been shown to increase the total amount of hepatic GSTs in rats. Primarily this study aimed to determine the induction of GSTs by benzoazoles (BAs) including benzoxazole (BX), 2-methylbenzoxazole (M-BX), 2,5-dimethyl benzoxazole (D-BX), benzothiazole (BT), aminobenzothiazole (A-BT) and 2-mercaptobenzothiazole (M-BT) in rats. Hepatic cytosol and poly(A)$^+$ mRNA were prepared from rats after oral administration of BX, BT, M-BX, D-BX, A-BT and M-BT for 5 consecutive days at doses of 1 mmol/kg. Western immunoblot and northern blot analysis were conducted with rabbit anti-GST Ya, Yb$_1$, Yb$_2$, Yc antibodies and cDNA probes containing = 500 bps in the specific coding regions of Ya, Yb$_1$, Yb$_2$, Yc$_1$, and Yc$_2$, respectively. All BAs increased the amount of enzymes and mRNA levels of GSTs. BT was the most effective inducer of GSTs among the compounds examined in this study. Although A-BT and M-BT, the derivatives of BT, induced GSTs, these chemicals had lesser effect on induction of GSTs than BT. The derivatives of BX also induced less GSTs than the parent compound and the addition of methyl group to the benzene ring of BX reduced the induction of GSTs. BAs had better inductive effects on the class $\alpha$(Ya, Yc) than class $\mu$ GSTs (Yb$_1$, Yb$_2$). BAs enhanced mRNA levels of GSTs in parallel with the protein levels. These results indicate that 1) most of BAs induced various isozymes of GSTs, 2) the induction of GSTs appears to be correlated with the chemical structure of the derivatives, and 3) the expression of GST by BAs is presumably under the transcriptional regulation.

• Journal of Power Electronics
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• 제15권1호
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• pp.146-159
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• 2015

Since the power capacity needed for the propulsion of large ships is very large, a multiphase AC induction propulsion mode is generally adopted to meet the higher requirements of reliability, redundancy and maintainability. This paper gives a detailed description of the development of a 20MW fifteen-phase PWM driver for advanced fifteen-phase propulsion induction motors with a special third-harmonic injection in terms of the main circuit hardware, control system design, experiments, etc. The adoption of the modular design method for the main circuit hardware design can make the enclosed mechanical structure simple and maintainable. It can also avoid the larger switch stresses caused by the multiple turn on of the IGBTs in conventional large-capacity converter systems. The use of the distributed controller design method based on a high-speed fiber-optic ring net for the control system can overcome such disadvantages as the poor reliability and long maintenance times arising from the conventional centralized controller which is designed according to point-to-point communication. Finally, the performance of the 20MW PWM driver is verified by experimentation on a new fifteen-phase induction propulsion motor.