• Journal of Korean Vacuum Science & Technology
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• v.6 no.2
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• pp.105-107
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• 2002

a-C:H films were coated on windows of mobile telephone by RF plasma chemical vapor deposition equipment made in our company. Thickness of the coatings is about 0.7 micrometers and they have high hardness, low friction coefficient, good adhesion, high optical transparency and chemical inertness. Knoop hardness of the diamond-like carbon films on glass substrate is 2328 kg/mm$^2$. The adherence between films and substrate is good and shows to be 69 N by scratching test. The optical performance is improved obviously owing to coat the film on it. The index of the coated windows is 2.5, transmission of visible light is larger than 90%, and transmission of ultraviolet light decreases by 30% and the ultraviolet light can be obstructed obviously. The coated glass also has self-clean effect and decontamination ability. The films have hydrophobic character and the soakage angle of water drop is larger than 90 degrees. The windows have fog-proof ability owing to eliminate the capillary phenomena in the inner surface. The physics and chemical properties of the coated windows are steady. Study indicates that the performance of a-C:H coated mobile phone windows are improved notably on wear-resistance, corrosion-proof and optical properties and it is excellent mobile windows protective coatings.

• Smart Structures and Systems
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• v.15 no.2
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• pp.469-488
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• 2015

Thermal loads, especially thermal gradients, have a considerable effect on the behaviors of large-scale bridges throughout their lifecycles. Bridge design specifications provide minimal guidance regarding thermal gradients for simple bridge girders and do not consider transversal thermal gradients in wide girder cross-sections. This paper investigates the three-dimensional thermal gradients of arch bridge girders by integrating long-term field monitoring data recorded by a structural health monitoring system, with emphasis on the vertical and transversal thermal gradients of wide concrete-steel composite girders. Based on field monitoring data for one year, the time-dependent characteristics of temperature and three-dimensional thermal gradients in girder cross-sections are explored. A statistical analysis of thermal gradients is conducted, and the probability density functions of transversal and vertical thermal gradients are estimated. The extreme thermal gradients are predicted with a specific return period by employing an extreme value analysis, and the profiles of the vertical thermal gradient are established for bridge design. The transversal and vertical thermal gradients are developed to help engineers understand the thermal behaviors of concrete-steel composite girders during their service periods.

• BMB Reports
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• v.42 no.11
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• pp.725-730
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• 2009

Cyclin E1 (CCNE1), a positive regulator of the cell cycle, controls the transition of cells from G1 to S phase. In numerous human tumors, however, CCNE1 expression is frequently dysregulated, while the mechanism leading to its dysregulation remains incompletely defined. Herein, we showed that CCNE1 expression was subject to post-transcriptional regulation by a microRNA miR-16-1. This was evident at protein level of CCNE1 as well as its mRNA level. Further evident by dual luciferase reporter assay revealed that two evolutionary conserved binding sites on 3' UTR of CCNE1 were the direct functional target sites. Moreover, we showed that miR-16-1 induced G0/G1 cell cycle arrest by targeting CCNE1 and siRNA against CCNE1 partially phenocopied miR-16-1-induced cell cycle phenotype whereas substantially rescued anti-miR-16-1- induced phenotype. Together, all these results demonstrate that miR-16-1 plays a vital role in modulating cellular process in human cancers and indicate the therapeutic potential of miR-16-1 in cancer therapy.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1483-1493
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• 2016

Multiple parallel inverters have multiple resonant frequencies that are influenced by many factors. This often results in stability and power quality problems. This paper develops a multiple input multiple output model of grid-connected inverter systems using a closed-loop transfer function. The influence factors of the resonant characteristics are analyzed with the developed model. The analysis results show that the resonant frequency is closely related to the number, type and composition ratio of the parallel inverters. To suppress resonance, a scheme based on virtual impedance is presented, where the virtual impedance is emulated in the vicinity of the resonance frequency. The proposed scheme needs one inverter with virtual impedance control, which reduces the design complexity of the other inverter controllers. Simulation and experimental tests are carried out on two single phase converter-based setups. The results validate the correctness of the model, the analytical results and the resonant suppressing scheme.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.4
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• pp.27-32
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• 2007

Gears, crucial components in modern precision machinery for power transmission mechanisms, are required to have low contacting noise with high torque transmission, which makes the use of gear-tooth profile modifications and gear-tooth surface crowning extremely efficient and valuable. Due to the shortcomings of current techniques, such as manual rectification, mechanical modification, and numerically controlled rectification, we propose a novel electrochemical gear-tooth profile modification method based on an artificial neural network control technique. The fundamentals of electrochemical tooth-profile modifications based on real-time control and a mathematical model of the process are discussed in detail. Due to the complex and uncertain relationships among the machining parameters of electrochemical tooth-profile modification processes, we used an artificial neural network to determine the required processing electric current as the tooth-profile modification requirements were supplied. The system was implemented and a practical example was used to demonstrate that this technology is feasible and has potential applications in the production of precision machinery.

• Structural Engineering and Mechanics
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• v.47 no.2
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• pp.265-286
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• 2013

A study on economic performances of consecutive multi-span suspension bridges is carried out. In this part of the study, material amount and structural cost estimation formulas of the bridges is derived based on the structural ultimate carrying capacity. The bridge cost includes the part of superstructure and the part of substructure. Three types of bridge foundations, bored piles, concrete caissons and floating foundations, are considered in substructure. These formulas are to be used for the parametric study of the bridge cost in order to define its more economical layout under different conditions in the part two of the study.

• BMB Reports
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• v.39 no.5
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• pp.571-577
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• 2006

Dendrolimus punctatus tetravirus (DpTV) has been identified as a new member of the genus Omegatetravirus of the family Tetraviridae that may be related serologically to Nudaurelia capensis virus ($N{\omega}V$). To establish the function of DpTV RNA genome and to better understand the mechanism of viral replication, the putative RNA-dependent RNA polymerase (RdRp) domain has been cloned and expressed in Escherichia coli. The recombinant protein was purified on a Ni-chelating HisTrap affinity column and demonstrated to initiate viral RNA synthesis in a primer-independent manner but not by terminal nucleotidyle transferase activity in the presence of $Mg^{2+}$ and RNA template. Mutation of the GDD to GAA interferes with the residues at the polymerase active site and metal ions, and thus renders the polymerase inactive.

• Structural Engineering and Mechanics
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• v.54 no.2
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• pp.305-317
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• 2015

Optimal sensor placement (OSP) is an integral component in the design of an effective structural health monitoring (SHM) system. This paper describes the implementation of a novel collaborative-climb monkey algorithm (CMA), which combines the artificial fish swarm algorithm (AFSA) with the monkey algorithm (MA), as a strategy for the optimal placement of a predefined number of sensors. Different from the original MA, the dual-structure coding method is adopted for the representation of design variables. The collaborative-climb process that can make the full use of the monkeys' experiences to guide the movement is proposed and incorporated in the CMA to speed up the search efficiency of the algorithm. The effectiveness of the proposed algorithm is demonstrated by a numerical example with a high-rise structure. The results show that the proposed CMA algorithm can provide a robust design for sensor networks, which exhibits superior convergence characteristics when compared to the original MA using the dual-structure coding method.

• Structural Engineering and Mechanics
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• v.36 no.3
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• pp.363-380
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• 2010

Materials which exhibit different elastic moduli in tension and compression are known as bimodular materials. The bimodular materials model, which is founded on the criterion of positive-negative signs of principal stress, is important for the structural analysis and design. However, due to the inherent complexity of the constitutive relation, it is difficult to obtain an analytical solution of a bimodular bending components except in particular simple problems. Based on the existent simplified model, this paper solves analytically bending thin plates with different moduli in tension and compression. By using the continuity conditions of stress components in unknown neutral layer, we determine the location of the neutral layer, and derive the governing differential equation for deflection, the flexural rigidity, and the internal forces in the thin plate. We also use a circular thin plate with bimodulus to illustrate the application of this solution derived in this paper. The results show that the introduction of different moduli has influences on the flexural stiffness of the bending thin plate.

• Advances in nano research
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• v.9 no.4
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• pp.295-307
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• 2020

The vibrational characteristics of Multi-Phase Nanocomposite (MPC) reinforced annular/circular plate under initially stresses are presented using the state-space formulation based on three-dimensional elasticity theory (3D-elasticity theory) and Differential Quadrature Method (DQM). The MPC reinforced annular/circular plate is under initial lateral stress and composed of multilayers with Carbon Nanotubes (CNTs) uniformly dispersed in each layer, but its properties change layer-by-layer along the thickness direction. The State-Space based Differential Quadrature Method (SS-DQM) is presented to examine the frequency behavior of the current structure. Halpin-Tsai equations and fiber micromechanics are used in the hierarchy to predict the bulk material properties of the multi-scale composite. A singular point is investigated for modeling the circular plate. The CNTs are supposed to be randomly oriented and uniformly distributed through the matrix of epoxy resin. Afterward, a parametric study is done to present the effects of various types of sandwich circular/annular plates on frequency characteristics of the MPC reinforced annular/circular plate using 3D-elasticity theory.