• 한국컴퓨터정보학회논문지
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• 제4권4호
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• pp.133-139
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• 1999

본 논문은 현재 사용되고 있는 케이블의 진단을 위해서 열화가중치라는 새로운 접근법을 사용하였다. 케이블은 상시에 높은 온도로 운전된다는 점, 수분이 접촉할 확률이 크다는 점에서 신뢰성 있고 효율적인 열화진단은 필수적이라고 할 수 있다. 종래의 연구는 수트리가 발생되는 절연층을 주 대상으로 삼았으나, 현대에 와서는 절연층뿐만 아니라, 내·외부 반도전층 또한 활발한 연구가 이루어지고 있다. 본 연구에서는 최근에 국내에서 제안된 열화가중치법을 이용하여 케이블의 열화인자가 될 수 있는 부분에 대하여 특성분석을 수행한 다음, 열화가중치를 부여하여 케이블의 최종적인 상태를 파악해 보았다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마
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• pp.59-63
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• 2000

The conventional tracking testing as IEC-60587 is widely used in surface aging measurement of outside insulator because those testing can carry out very short time in Lab testing. Also IEC-60587 testing is able to offer the standard judgement of relative degradation level of outside HV machine. Therefore it is very useful method compare to previous conventional tracking testing method and effective Lab testing method. But surface discharges(SD) have very complex characteristics of discharge pattern so it is required estimation research to development of precise analysis method. In recent, the study of IIR-camera is carrying out discover of temperature of power equipment through condition diagnosis and system development of degradation diagnosis. In this study, SD occurred from IEC-60587 is measured with partial temperature distribution in real time, the degradation grade of SD is analyzed through produced patterns in IEC-60587 according to applied time.

• Structural Engineering and Mechanics
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• 제49권6호
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• pp.775-792
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• 2014

Static loading tests were carried out in this study to investigate the effect of bar cutoff on the resistance of RC beam-column sub-assemblages under column loss. Two specimens were designed with continuous main reinforcement. Four others were designed with different types of bar cutoff in the mid-span and/or the beam-end regions. Compressive arch and tensile catenary responses of the specimens under gravitational loading were compared. Test results indicated that those specimens with approximately equal moment strength at the beam ends had similar peak loading resistance in the compressive arch phase but varied resistance degradation in the transition phase because of bar cutoff. The compressive bars terminated at one-third span could help to mitigate the degradation although they had minor contribution to the catenary action. Among those cutoff patterns, the K-type cutoff presented the best strength enhancement. It revealed that it is better to extend the steel bars beyond the mid-span before cutoff for the two-span beams bridging over a column vulnerable to sudden failure. For general cutoff patterns dominated by gravitational and seismic designs, they may be appropriately modified to minimize the influence of bar cutoff on the progressive collapse resistance.

• Journal of Advanced Marine Engineering and Technology
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• 제28권8호
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• pp.1203-1210
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• 2004

It was reported recently that the pump head degradation near the best efficiency point from single-phase flow to the break-down due to air entrainment became less in a screw-type centrifugal pump than in a general centrifugal pump. In this paper, I carried out internal pressure measurements and visualizations, and investigated the various physical phenomena occurring inside a screw-type centrifugal pump operated in air-water two-phase flow. The results could give some characteristics about the degradation of pump performance on air-water two-phase flow.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.560-562
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• 2009

In this paper, we proposed a simple method of decreasing the off current generated by degradation for improve the electrical characteristics such as mobility and on/off current ratio by making the line patterns on the pentacene surface between the electrodes using atomic force microscope (AFM) lithography.

• 한국세라믹학회지
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• 제46권3호
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• pp.263-270
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• 2009

The effect of photoelectrocatalytic (PEC) degradation for different dyes with the CNT/$TiO_2$ electrode was studied. The prepared electrode was characterized with surface properties, structural crystallinity, elemental identification, and PEC activity. The $N_2$ adsorption data showed that the composites had decreased surface area compared with the pristine CNT. This indicated the blocking of micropores on the surface of CNT, which was further supported by observation via FESEM. XRD patterns of the composites showed that the CNT/$TiO_2$ composite contained a mixing anatase and rutile phase. EDX spectra showed the presence of C, O and Ti peaks for all samples. The decomposition efifciency of the prepared electrode was evaluated by the PEC degradation of three dyes (methylene blue (MB), rhodamine B (RH.B), methyl orange (MO)). The variations of the FT-IR spectra and pH value of dye solutions were measured during the PEC system; it was found that the CNT/$TiO_2$ electrode has better PEC degradation for MB solution than that of RH.B and MO. The proposed degradation mechanism was present.

• Environmental Engineering Research
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• 제18권1호
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• pp.21-28
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• 2013

In this study, the applicability of visible light-emitting-diodes (LEDs) to the photocatalytic degradation of indoor-level trichloroethylene (TCE) and perchloroethylene (PCE) over N-doped $TiO_2$ (N-$TiO_2$) was examined under a range of operational conditions. The N-$TiO_2$ photocatalyst was calcined at $650^{\circ}C$ (labeled N-650) showed the lowest degradation efficiencies for TCE and PCE, while the N-$TiO_2$ photocatalysts calcined at $350^{\circ}C$, $450^{\circ}C$, and $550^{\circ}C$ (labeled as N-350, N-450, and N-550, respectively) exhibited similar or slightly different degradation efficiencies to those of TCE and PCE. These results were supported by the X-ray diffraction patterns of N-350, N-450, N-550, and N-650. The respective average degradation efficiencies for TCE and PCE were 96% and 77% for the 8-W lamp/N-$TiO_2$ system, 32% and 20% for the violet LED/N-$TiO_2$ system, and ~0% and 4% for the blue LED/N-$TiO_2$ system. However, the normalized photocatalytic degradation efficiencies for TCE and PCE for the violet LED-irradiated N-$TiO_2$ system were higher than those from the 8-W fluorescent daylight lamp-irradiated N-$TiO_2$ system. Although the difference was not substantial, the degradation efficiencies exhibited a decreasing trend with increasing input concentrations. The degradation efficiencies for TCE and PCE decreased with increasing air flow rates. In general, the degradation efficiencies for both target compounds decreased as relative humidity increased. Consequently, it was indicated that violet LEDs can be utilized as energy-efficient light sources for the photocatalytic degradation of TCE and PCE, if operational conditions of N-$TiO_2$ photocatalytic system are optimized.

• BMB Reports
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• 제42권9호
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• pp.552-560
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• 2009

Cyclooxygenases (COX-1 and COX-2) are ER-resident proteins that catalyze the committed step in prostanoid synthesis. COX-1 is constitutively expressed in many mammalian cells, whereas COX-2 is usually expressed inducibly and transiently. Abnormal expression of COX-2 has been implicated in the pathogenesis of chronic inflammation and various cancers; therefore, it is subject to tight and complex regulation. Differences in regulation of the COX enzymes at the posttranscriptional and posttranslational levels also contribute significantly to their distinct patterns of expression. Rapid degradation of COX-2 mRNA has been attributed to AU-rich elements (AREs) at its 3’UTR. Recently, microRNAs that can selectively repress COX-2 protein synthesis have been identified. The mature forms of these COX proteins are very similar in structure except that COX-2 has a unique 19-amino acid (19-aa) segment located near the C-terminus. This C-terminal 19-aa cassette plays an important role in mediation of the entry of COX-2 into the ER-associated degradation (ERAD) system, which transports ER proteins to the cytoplasm for degradation by the 26S proteasome. A second pathway for COX-2 protein degradation is initiated after the enzyme undergoes suicide inactivation following cyclooxygenase catalysis. Here, we discuss these molecular determinants of COX-2 expression in detail.

• 한국전기전자재료학회논문지
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• 제11권10호
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• pp.940-945
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• 1998

In this paper, we obtained the data, which is required in training the neural network and diagnosing the degradation degree, by introducing the AE detection that is effective method in ordinary degradation diagnosis on activation. Aa the results of generalization tests by appling neural network to the unknown AE patterns obtained from two kinds of specimen, firstly as to evaluate an objective performance of neural network, the recognition ration for no-void specimen and 1[mm] -void specimen are appeared to be 98.9% and 92.5%, respectively. Also, in the evaluation of the adaptability of neural network with a new type of 0.2[mm] -void specimen, it is confirmed that the result appears to be 64% of recognition ratio at 94% of confidence interval coefficient in expectation output 0.2. On the other hand, the recognition capability of the neural network was confirmed by data from no-void and 1[mm] void specimen. The results prove the promising possibility of the application of ANN to discriminate specific void affecting as main degradation source at partial discharge condition in insulator containing multi-void by accummulated data base.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
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• pp.71-74
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• 2001

The conventional tracking testing as IEC-60587 is widely used In surface aging measurement of outside insulator because those testing can carry out very short time in Lab testing. Also IEC-60587 testing is able to offer the standard judgement of relative degradation level of outside HV machine. Therefore it is very useful method compare to previous conventional tracking testing method and effective Lab testing method. But surface discharges(SD) have very complex characteristics of discharge pattern so it is required estimation research to development of precise analysis method. In recent, the study of IIR-camera is carrying out discover of temperature of power equipment through condition diagnosis and system development of degradation diagnosis. In this study, SD occurred from IEC-60587 is measured with partial temperature distribution in real time, the degradation grade of SD is analyzed through produced patterns in IEC-60587 according to applied time.