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Wu T.,Ship Research Institute | Cheng K.,Brunel University
International Journal of Advanced Manufacturing Technology | Year: 2014

In an effort to prolong the tool life and improve the tooling performance in micro cutting, it is attractive and promising to apply diamond-like carbon (DLC) coatings on micro tools. Comprehensive understandings of micro cutting performance under various coating circumstances are essential for choosing optimum coating conditions so as for potentially improving cutting tool designs. In the study, the cutting characteristics of a DLC-coated tool has been extensively evaluated and compared with those of an uncoated tool under constant and various uncut chip thickness (UCT) using 2D plane-strain finite element method (FEM). The thermo-mechanical modelling approach has been validated at different UCT in micro milling. Besides, the influence of coating friction coefficient, coating thickness as well as UCT on the cutting forces and tool temperatures has been determined and analysed through design of experiment. It is found that appropriate UCT in micro cutting is of the greatest importance for achieving desirable coating performance of micro tools. © 2014 Springer-Verlag London. Source

Li M.-H.,Central China Normal University | Yang H.-L.,Central China Normal University | Hou X.-W.,Central China Normal University | Tian Y.,Huazhong University of Science and Technology | Hou D.-Y.,Ship Research Institute
Progress in Electromagnetics Research | Year: 2010

In this paper, we present the design, simulation, and measurement of a dual-band metamaterial absorber in the microwave region. Simulated and experimental results show that the absorber has two perfect absorption points near 11.15GHz and 16.01GHz. Absorptions under different polarizations of incident EM waves are measured with magnitude of over 97% at low-frequency peak and 99% at high-frequency peak respectively. Current distribution at the dual absorptive peaks is also given to study the physical mechanism of power loss. Moreover, it is verified by experiment that the absorptions of this kind of metamaterial absorber remain over 90% at the low-frequency peak and 92% at the high-frequency peak with wide incident angles ranging from 0° to 60° for both transverse electric wave and transverse magnetic wave. Source

Yang Y.,Wuhan University of Technology | Zhang G.,Wuhan University of Technology | Xu W.,Ship Research Institute
Journal of Colloid and Interface Science | Year: 2012

In this study, we prepared a new visible light induced plasmonic photocatalyst AgAgClTiO 2/rectorite using a facile deposition-photoreduction method. The catalysts were characterized using X-ray diffraction (XRD), UV-visible diffused reflectance spectra (UV-vis DRS), Raman spectra, high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The as-prepared AgAgClTiO 2/rectorite powders exhibited an efficient photocatalytic activity for the degradation of acid orange (ARG) and 4-nitrophenol (4-NP) under visible light irradiation (λ>400nm). Moreover, the mechanism suggested that the high photocatalytic activity is due to the charge separation and the surface plasmon resonance of metallic Ag particles in the region of visible light. The active species measurements suggested that HO is not the dominant photooxidant. Direct hole transfers and O2- were involved as the active species in the photocatalytic reaction. © 2012 Elsevier Inc. Source

Chen C.,Ship Research Institute
2014 17th IEEE International Conference on Intelligent Transportation Systems, ITSC 2014 | Year: 2014

As one important step of area-coordination in traffic management systems, the technology of network zoning is indispensable. On this topic, this paper introduces our work to reduce the burden of engineers on this problem. Firstly, inspired by the pros and cons of previous researches, we found three principles of zoning. Then, one model is proposed to measure the relationship between intersections for automatic identification of hierarchical characteristic of traffic network and adapt to the alternating busy-idle traffic environment. Under one certain traffic scene, a higher score of model means that two intersections have closer relationship and the related link has a higher coordination priority. Hence, using this model, we can rank the coordination priority of links in the network. Lastly, considering traffic network is one kind of directed spatial network, one network zoning method based on community detection is detailed to handel the characteristics of traffic network. We use a series of experiments on the traffic network in Tianhe area of Guangzhou to illustrate the effectiveness of this method and can be employed to handle large scale traffic networks. © 2014 IEEE. Source

Yin J.-C.,Dalian Maritime University | Zou Z.-J.,Shanghai JiaoTong University | Xu F.,Ship Research Institute | Wang N.-N.,Dalian Maritime University
Neurocomputing | Year: 2014

For the online prediction of nonlinear systems with characteristics of time-varying dynamics and uncertainty, a sequential grey prediction approach is proposed based on the online sequential extreme learning machine (OS-ELM). The grey processing of time series alleviates the unfavorable effects of uncertainty in measurement data; the extremely fast learning speed and high generalization accuracy of OS-ELM enable online application of the sequential grey prediction approach. Ship's roll motion at sea is a complex nonlinear process with time-varying dynamics. Its dynamics also involves uncertainty caused by wind, random waves and rudder actions. In this paper, the proposed OS-ELM-based grey prediction approach is implemented for online ship roll prediction. The simulation of prediction is based on measurement data obtained from sea trials of the scientific research and training ship Yu Kun. Simulation results of ship roll prediction demonstrate the effectiveness and efficiency of the proposed grey neural prediction approach in dealing with time-varying nonlinear system with uncertainty. © 2013 Elsevier B.V. Source

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