• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
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• pp.75-78
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• 2001

Recently, the HFPD measurement testing is widely used in partial discharge measurement of HV machines because HFPD measurement testing receives less influence of external noise and has a merit of good sensitivity. Also HFPD testing is able to offer the judgement standard of degradation level of HV machine and can detect discharge signals in live-line. Therefore it is very useful method compare to previous conventional PD testing method and effective diagnosis method in power transformer that requires live-line diagnosis. But partial discharges have very complex characteristics of discharge pattern so it is required continuous research to development of precise analysis method. In recent, the study of partial discharge is carrying out discover of initial defect of power equipment through condition diagnosis and system development of degradation diagnosis using HFPD(High Frequency Partial Discharge) detection. In this study, simulated transformer is manufactured and HFPD occurred from transformer is measured with broad band antenna in real time, the degradation grade of transformer is analyzed through produced patterns in simulated transformer according to applied voltages.

• BMB Reports
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• 제48권8호
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• pp.431-437
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• 2015

Notch signaling plays a pivotal role in cell fate determination, cellular development, cellular self-renewal, tumor progression, and has been linked to developmental disorders and carcinogenesis. Notch1 is activated through interactions with the ligands of neighboring cells, and acts as a transcriptional activator in the nucleus. The Notch1 intracellular domain (Notch1-IC) regulates the expression of target genes related to tumor development and progression. The Notch1 protein undergoes modification after translation by posttranslational modification enzymes. Phosphorylation modification is critical for enzymatic activation, complex formation, degradation, and subcellular localization. According to the nuclear cycle, Notch1-IC is degraded by E3 ligase, FBW7 in the nucleus via phosphorylation-dependent degradation. Here, we summarize the Notch signaling pathway, and resolve to understand the role of phosphorylation in the regulation of Notch signaling as well as to understand its relation to cancer. [BMB Reports 2015; 48(8): 431-437]

• Genomics & Informatics
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• 제6권2호
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• pp.72-76
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• 2008

Hypoxia-inducible factor $1{\alpha}\;(HIF1{\alpha})$ is a transcription factor that plays a key role in the adaptation of cells to low oxygen stress and oxygen homeostasis. The oxygen-dependent degradation (ODD) domain of $HIF1{\alpha}$ is responsible for the negative regulation of $HIF1{\alpha}$ in normoxia. The interactions of the $HIF1{\alpha}$ ODD domain with partner proteins such as von Hippel-Lindau tumor suppressor (pVHL) and p53 are mediated by two sequence motifs, the N- and C-terminal ODD(NODD and CODD). Multiple sequence alignment with $HIF1{\alpha}$ homologs from human, monkey, pig, rat, mouse, chicken, frog, and zebrafish has demonstrated that the NODD and CODD motifs have noticeably high conservation of the primary sequence across different species and isoforms. In this study, we carried out molecular dynamics simulation of the structure of the $HIF1{\alpha}$ CODD motif in complex with the p53 DNA-binding domain (DBD). The structure reveals specific functional roles of highly conserved residues in the CODD sequence motif of $HIF1{\alpha}$ for the recognition of p53.

• 한국전기전자재료학회논문지
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• 제20권2호
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• pp.188-193
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• 2007

Tracking and erosion of Poly Methyl Methacrylate (PMMA) and the suppression mechanism of alumina trihydrate were investigated in the present study The conventional testing as IEC-60587 is widely used in surface aging measurement of outdoor insulator those testing can carry out very short time for Lab testing. Also IEC-60587 testing is able to offer the standard judgement of relative degradation level of outdoor HV system. Therefore it is very useful method compare to previous conventional tracking 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 IRR-Camera is carrying out discover of temperature of power equipment through condition diagnosis and system development of degradation diagnosis. In this paper, SD occurred from IEC-60587 is measured with the surface temperature of weibull distribution in real time, the degradation grade of SD is analyzed through produced patterns in IEC-60587 using Infrared Radiation(IRR) camera.

• 한국해양공학회지
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• 제13권2호통권32호
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• pp.99-107
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• 1999

Boiler high-temperature pipelines such as main steam pipe, header and steam drum in fossil power plants are degraded by creep damage due to severe operationg conditions which are high temperature and high pressure for an extended period time. Such material degradation leads to various component failures causing serious accidents at the plants. Conventional measurement techniques such as replica method, electric resistance method, and hardness test method have such disadvantages as complex preparation and measurement procedures, too many control parameters, and therefore, low practicality and they were applied only to component surfaces with good accessibility. In this paper, artificial creep degradation test and ultrasonic measurement for their creep degraded specimens have been carried out for the purpose of evaluation for creep damage which can occur in high-temperature pipeline of fossil power plant. Absolute measuring method of quantitative ultrasonic measurement for material degradation was established, and long term creep degradationtests using life prediction formula were carried out. As a result of ultrasonic tests for crept specimens, we confirmed that the sound velocity decreased and the attenuation coefficient linearly increased in proportion to the increase of creep fractiin(${\phi}$c).

• BMB Reports
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• 제51권3호
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• pp.143-150
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• 2018

The Hippo signaling pathway plays an essential role in adult tissue homeostasis and organ size control. Abnormal regulation of Hippo signaling can be a cause for multiple types of human cancers. Since the awareness of the importance of the Hippo signaling in a wide range of biological fields has been continually grown, it is also understood that a thorough and well-rounded comprehension of the precise dynamics could provide fundamental insights for therapeutic applications. Several components in the Hippo signaling pathway are known to be targeted for proteasomal degradation via ubiquitination by E3 ligases. ${\beta}-TrCP$ is a well-known E3 ligase of YAP/TAZ, which leads to the reduction of YAP/TAZ levels. The Hippo signaling pathway can also be inhibited by the E3 ligases (such as ITCH) which target LATS1/2 for degradation. Regulation via ubiquitination involves not only complex network of E3 ligases but also deubiquitinating enzymes (DUBs), which remove ubiquitin from its targets. Interestingly, non-degradative ubiquitin modifications are also known to play important roles in the regulation of Hippo signaling. Although there has been much advanced progress in the investigation of ubiquitin modifications acting as regulators of the Hippo signaling pathway, research done to date still remains inadequate due to the sheer complexity and diversity of the subject. Herein, we review and discuss recent developments that implicate ubiquitin-mediated regulatory mechanisms at multiple steps of the Hippo signaling pathway.

• Earthquakes and Structures
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• 제9권5호
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• pp.957-981
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• 2015

Earthquakes occur as a cluster in many regions around the world where complex fault systems exist. The repeated shaking usually induces accumulative damage to affected structures. Damage accumulation in structural systems increases their level of degradation in stiffness and also reduces their strength. Many existing analytical tools of modeling RC structures lack the salient damage features that account for stiffness and strength degradation resulting from repeated earthquake loading. Therefore, these tools are inadequate to study the response of structures in regions prone to multiple earthquakes hazard. The objective of this paper is twofold: (a) develop a tool that contains appropriate damage features for the numerical analysis of RC structures subjected to more than one earthquake; and (b) conduct a parametric study that investigates the effects of multiple earthquakes on the response of RC moment resisting frame systems. For this purpose, macroscopic constitutive models of concrete and steel materials that contain the aforementioned damage features and are capable of accurately capturing materials degrading behavior, are selected and implemented into fiber-based finite element software. Furthermore, finite element models that utilize the implemented concrete and steel stress-strain hysteresis are developed. The models are then subjected to selected sets of earthquake sequences. The results presented in this study clearly indicate that the response of degrading structural systems is appreciably influenced by strong-motion sequences in a manner that cannot be predicted from simple analysis. It also confirms that the effects of multiple earthquakes on earthquake safety can be very considerable.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마
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• pp.50-54
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• 2000

Recently, the HFPD measurement testing is widely used in partial discharge measurement of HV machines because HFPD measurement testing receives less influence of external noise and has a merit of good sensitivity. Also HFPD testing is able to offer the judgement standard of degradation level of HV machine and can detect discharge signals in live-line. Therefore it is very useful method compare to previous conventional PD testing method and effective diagnosis method in power transformer that requires live-line diagnosis. But partial discharges have very complex characteristics of discharge pattern so it is required continuous research to development of precise analysis method. In recent, the study of partial discharge is carrying out discover of initial defect of power equipment through condition diagnosis and system development of degradation diagnosis using HFPD(High Frequency Partial Discharge) detection. In this study, simulated transformer is manufactured and HFPD occurred from transformer is measured with broad band antenna in real time, the degradation grade of transformer is analyzed through produced patterns in simulated transformer according to applied voltages.

• Archives of Pharmacal Research
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• 제15권2호
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• pp.176-183
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• 1992

The stabilizing effects of $\alpha$-$\beta$-$\gamma$- and dimethyl-$\beta$-cyclodextrins $(\alpha$-, $\beta$-, $\gamma$- and DM-$\beta-$-CyDs) on the degradation of hydrocortisone 17-butyrate (HC-17B) in aqueous solution was investigated. Hc-17B underwent a facile hydroxide ion-catalyzed rearrangement to the less active 21-butyrate ester by the apparent first-order kinetics, and maximum stability of HC-17B was obtained at around pH 4.0. The stability of HC-17B was increased by inclusion complexation with $\alpha$-, $\gamma$- and DM-$\beta$-CyD in the pH range of 2.0-8.0 examined, whereas $\beta$-CyD accelerated the degradation of HC-17B at the pH higher than 5.0. The effects of ionic strength, solvent, temperature and CyD concentration were also investigated. Stability constants and apparent degradation rate constants of HC-17B-$\gamma$-CyD and HC-17B-DM-$\beta$-CyD complexes were determined kinetically on the basis of 1:1 complexation. The results suggested that the inclusion complexation with $\gamma$-CyD or DM-$\beta$-CyD was most useful means to enhance the stability of the steroid.

• Biodesign
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• 제6권4호
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• pp.100-102
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• 2018

Autophagy is a degradation pathway that targets many cellular components and plays a particularly important role in protein degradation and recycling. This process is very complex and several proteins participate in this process. One of them, P62/SQSTM1, is related to the N-end rule and induces protein degradation through autophagy. The P62/SQSTM1 makes a huge oligomer, and this oligomerization is known to play an important role in its mechanism. This oligomerization takes two steps. First, the PB1 domain of P62/SQSTM1 makes the base oligomer, and then, when the ligand binds to the ZZ domain of P62/SQSTM1, it induces a higher oligomer by the disulfide bond of the two cysteines. To understand the oligomerization mechanism of P62/SQSTM1, we need to know the dimerization of the PB1 domain. In this study, crystals of PB1 dimer were made and the crystals were diffracted by X-ray to collect usable data up to 3.2A. We are analyzing the structure using the molecular replacement (MR) method.