• YAKHAK HOEJI
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• v.60 no.3
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• pp.135-140
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• 2016

Heat shock protein 90 (Hsp90) is a ubiquitous molecular chaperone, which is associated with stabilization of many oncogenic proteins for cancer cell survival. Hsp90 is overexpressed 2-10 fold higher in cancer cells than normal cells. Due to its potential to simultaneously disable multiple signaling pathway, Hsp90 has been identified as a validated target for cancer therapy. Accordingly, we designed and synthesized 2',4'-dimethoxychalcone derivatives to inhibit Hsp90 chaperone function. Among 2',4'-dimethoxychalcone derivatives, we found that compound 1g disrupted Hsp90 chaperoning function and impaired the growth of cancer cells. These findings indicated that 1g could serve a potential lead compound to target Hsp90 in cancer chemotherapy.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.1
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• pp.38-46
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• 2021

The Organization's ability to respond to social disasters has begun to be treated as important through social shock situations that have never been experienced, such as COVID-19. Among them, the ability to respond to unexpected risks and resilience is emerging. Since social disasters such as infectious diseases are periodically repeated, compounded, and enlarged, they develop into a global crisis situation, so this crisis response capability is treated as national competitiveness. Therefore, this study aims to improve the organization's response capability in terms of risk response and resilience under rapid social disasters such as COVID-19. The aviation safety field was taken as an example. From the Safety-II perspective, safety management focuses on the ability to resilience in response to system vulnerabilities in various situations. In this study, I intend to apply RAG(Resilience Assessment Grid) of Respond, Monitor, Learn and Anticipate, the four major potential of resilience engineering. Based on Hollnagel's research, potential elements were classified into four, and items were organized through an expert panel using Delphi techniques. The final configured RAG items are 15 Respond, 15 Monitor, 15 Learn and 11 Anticipate. The RAG was evaluated by 42 experts in the field of aviation safety.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.315-318
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• 2009

Electric shock is the accident caused by the current through a person or animal's body. That is characterized by the physiological effects. In this paper, we evaluate performance of protection against electric shocks for TT and TN grounding systems which are used by a low voltage consumer nowadays. The performance of protection against electric shocks for TT grounding system is very excellent in equipotential area of the third class grounding, but the performance is poor outside the equipotential area. The performance of protection against electric shocks for TN grounding system is excellent because the potential difference is less than 50V. Accordingly, the performance of protection for TN grounding system is good as compared with that for TT grounding System.

• Journal of computational fluids engineering
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• v.12 no.3
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• pp.20-28
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• 2007

A fast and robust method of grid generation to multiple functions has been developed for flow analysis in three dimensional space. It is based on the Non-Uniform Rational B-Spline(NURBS) of an approximation method. Many of NURBS intrinsic properties are introduced and much more easily understood. The grid generation method, details of numerical implementation. examples of application, and potential extensions of the current method are illustrated in this paper. The object of this study is to develop the surface grid generation and the grid cluster techniques capable of resolving complex flows with shock waves, expansion waves, shear layers. The knot insert method of Non-Uniform Rational B-Spline seems well worked. In addition, NURBS has been widely utilized to generate grids in the computational fluid dynamics community. Computational examples associated with practical configurations have shown the utilization of the algorithm.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.4
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• pp.410-418
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• 2007

This article suggests the methods to investigate adverse movement across global stock markets arising from insolvency of subprime mortgage in U.S. Our application deals with asymptotic tail dependence of daily stock index returns (KOSPI, DJIA, Shanghai Composite) of three countries; Korea, U.S., and China, over specific period via extreme value theory and copula functions. Daily stock index returns among three countries show higher extremal dependence during the period exposed to systematic shock. We confirm that extreme value theory and copula functions have potential to well describe the extreme dependence between three countries' daily stock index returns.

• Computers and Concrete
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• v.6 no.5
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• pp.377-390
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• 2009

In this paper an improved one-dimensional frame element for modelling of reinforced concrete beams and columns subjected to impact is presented. The model is developed in the framework of a flexibility fibre element formulation that ignores the shear effect at material level. However, a simple shear cap is introduced at section level to take account of possible shear failure. The effect of strain rate at the fibre level is taken into account by using the dynamic increase factor (DIF) concept for steel and concrete. The capability of the formulation for estimating the element response history is demonstrated by some numerical examples and it is shown that the developed 1D element has the potential to be used for dynamic analysis of large framed structures subjected to impact of air blast and rigid objects.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1478-1481
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• 2012

Geldanamycin (GM) and its analogs are important anticancer agents that inhibit heat shock protein (Hsp) 90, which is a major chaperone protein in cancer cells. Accordingly, based on interest in obtaining novel natural GM derivatives, the potential of Streptomyces hygroscopicus JCM4427, a GM producer, was explored for novel natural GM derivative(s), resulting in the discovery of new GM analogs as a biosynthetic shunt product and intermediates from its fermentation broth. In this study, the fermentation, isolation, structure determination, and biological activity of the compounds, two new tetracyclic thiazinogeldanamycin (1) and 19-hydroxy-4,5-dihydrogeldanamycin (3), together with the three known 4,5-dihydrothiazinogeldanamycin (2), reblastatin (4), and 17-demethoxy-reblastatin (5), are described.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.9-13
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• 2008

The moving load such as a shock wave in a pipe propagates with a specific velocity. This internal load speed determines the level of flexural wave excitation and the possibility of resonant response leading to a large deformation. In this paper, we present particular solutions of displacements and the resonance conditions when the moving load is propagating in a pipe. These analytical results are compared to numerical simulations obtained using a hydrocode. We expect to identify potential explosion hazards in the general power industries.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.4
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• pp.118-125
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• 1991

Acoustic microscopy has attracted much interest recently as potential nondestructive evaluation technique for detecting and sizing defects of surface and sub-surface. Also acoustic emission testing method has been developed for detecting microcracks which is more than 30${\mu}m$ in length quantitatively on ceramics. In the present paper, acoustic emission during the four point bending test in hot-pressed sintered $Si_3N_4$ specimen which was stressed by thermal shock, has been measured by high sensitive sensing system. The surface and sub-surface cracks were detected by scanning acoustic micrscope of 800 MHz and conventional ultrasonic testing in C-scope image. The purpose was to investigate the location and size of cracks by SAM and AE technique, whose experimental data demonstrate good for detecting microcracks.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.213-219
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• 2001

This paper describes the power line proximity warning device for mobile crane by using the induced voltage measurement method. A mobile crane worker can be easily exposed to dangerous electrical shock and the electrocution while this are working at near the high-voltage electrical lines. In this paper, the derivation electric-potential of the power lines are simulated and microprocessor-based detecting device and transmitter/receiver modules are introduced to show a solution for the dangerous mobile crane working environment.