Li J.,Hanshan Normal University
Optics Express | Year: 2014
In this paper, a novel secure optimal image watermarking scheme using an encrypted gyrator transform computer generated hologram (CGH) in the contourlet domain is presented. A new encrypted CGH technique, which is based on the gyrator transform, the random phase mask, the three-step phase-shifting interferometry and the Fibonacci transform, has been proposed to produce a hologram of a watermark first. With the huge key space of the encrypted CGH, the security strength of the watermarking system is enhanced. To achieve better imperceptibility, an improved quantization embedding algorithm is proposed to embed the encrypted CGH into the low frequency sub-band of the contourlettransformed host image. In order to obtain the highest possible robustness without losing the imperceptibility, particle swarm optimization algorithm is employed to search the optimal embedding parameter of the watermarking system. In comparison with other method, the proposed watermarking scheme offers better performances for both imperceptibility and robustness. Experimental results demonstrate that the proposed image watermarking is not only secure and invisible, but also robust against a variety of attacks. © 2014 Optical Society of America.
Li L.,Hanshan Normal University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012
In this paper, we consider two related problems, unambiguous discrimination of quantum mixed states and unambiguously conveying classical messages using Einstein-Podolsky-Rosen (EPR) pairs. The main technical contributions are as follows. First, we present a general upper bound on the success probability for unambiguous discrimination among arbitrary N mixed quantum states with given a priori probability, which can be directly used to the unambiguous communication setting. Second, we propose a sufficient condition to show that a new upper bound can be achievable, and construct examples to clarify the relationship between the upper bound we derive and the existing upper bounds presented by other authors. Third, in the issue of conveying classical messages using EPR pairs, we also derive an upper bound on the success probability for unambiguously decoding, where Alice wants to convey n bit classical information to Bob by sending m quantum bits. © 2012 American Physical Society.
Li J.,Hanshan Normal University
Applied Optics | Year: 2010
Robustness against geometric attacks is one of the most important issues in digital watermarking. A novel geometric robust watermarking scheme that uses computer-generated holograms as the watermark is presented. To maintain imperceptibility and robustness, a quantization embedding algorithm is adopted to embed the mark hologram into the low-frequency subband of the wavelet-transformed host image. In the detection process, the geometric distorted watermarked images are recovered first by the proposed improved geometric correction method, which is based on the scale invariant feature transform, the invariant centroid, and the pulse coupled neural network. Then the mark holograms are extracted from the recovered images. In comparison with the traditional geometric estimation method, the suggested improved geometric correction method can estimate the geometric distortion parameters more accurately and needs less auxiliary information. Compared with other watermark schemes using digital holograms, the proposed method has the distinct advantage of robustness to geometric attacks. The experimental results demonstrate that the proposed method has good robustness to resist geometric attacks and common attacks including rotation, scaling, translation, image flipping, combined attacks, filtering, occlusion, cropping, and JPEG compression. © 2010 Optical Society of America.
Huang M.,Hanshan Normal University
Computers and Mathematics with Applications | Year: 2010
By using an impulsive inequality and the Riccati transformation technique on time scales, several oscillation criteria are established for the second order nonlinear dynamic equations on time scales with impulses. Examples are given to show that the impulses play a dominant part in the oscillations of dynamic equations on time scales. © 2009 Elsevier Ltd. All rights reserved.
Li W.-J.,Hanshan Normal University
Catalysis Communications | Year: 2014
A series of new chiral benzene-based tetraoxazoline ligands were prepared in good yields through the reaction of 1,2,4,5-benzenetetracarboxylic acid and chiral β-amino alcohols by continuous removal of water, and the asymmetric Friedel-Crafts alkylation of indole derivatives with nitroalkenes was tested using the chiral catalysts, which were generated in situ by refluxing the above ligands and anhydrous zinc chloride in solvent. In most case, good yields (up to 99%) and excellent enantioselectivities (up to 98% ee) were obtained. © 2014 Elsevier B.V.
Chen C.,Hanshan Normal University
Physics and Chemistry of Liquids | Year: 2010
An ionic liquid (IL) containing an appended 3-chloro-2-hydroxypropyl functionality group 1-(3-chloro-2-hydroxypropyl)-3-methyl imidazolium chloride was synthesised by the reaction of N-methyl imidazole, hydrochloric acid and epichlorohydrin. The ionic liquid showed reasonably high conductivity and heat stability up to 230°C. Its structures were characterised by FT-IR, 1H NMR and 13C NMR spectra. The physical characteristics of the ionic liquid, such as conductivity and solvation abilities have been investigated. Due to its high polarity, the IL is able to dissolve many inorganic salts, and due to hydroxyl-rich microenvironment, it is able to dissolve cellulose go up to 10 (wt%). The ILs can be used for synthesising other ILs or polyelectrolyte. © 2010 Taylor & Francis.
Gengzhong Z.,Hanshan Normal University |
Qiumei L.,Hanshan Normal University
Advances in Information Sciences and Service Sciences | Year: 2012
Survivability is one of the most hot issues in WSNs (Wireless Sensor Networks). With complex network theory, a topology evolution model for scale-free WSNs is proposed, energy and degree saturation are considered in the design of the model. Dynamic analysis and simulations show that the evolution model has the characteristics of scale-free and topologies formed by the model have a good survivability under random and deliberate attack.
Xu C.-X.,Zhejiang University |
Xu C.-X.,Hanshan Normal University |
Yin X.-F.,Zhejiang University
Journal of Chromatography A | Year: 2011
A chip-based microfluidic system for high-throughput single-cell analysis is described. The system was integrated with continuous introduction of individual cells, rapid dynamic lysis, capillary electrophoretic (CE) separation and laser induced fluorescence (LIF) detection. A cross microfluidic chip with one sheath-flow channel located on each side of the sampling channel was designed. The labeled cells were hydrodynamically focused by sheath-flow streams and sequentially introduced into the cross section of the microchip under hydrostatic pressure generated by adjusting liquid levels in the reservoirs. Combined with the electric field applied on the separation channel, the aligned cells were driven into the separation channel and rapidly lysed within 33. ms at the entry of the separation channel by Triton X-100 added in the sheath-flow solution. The maximum rate for introducing individual cells into the separation channel was about 150. cells/min. The introduction of sheath-flow streams also significantly reduced the concentration of phosphate-buffered saline (PBS) injected into the separation channel along with single cells, thus reducing Joule heating during electrophoretic separation. The performance of this microfluidic system was evaluated by analysis of reduced glutathione (GSH) and reactive oxygen species (ROS) in single erythrocytes. A throughput of 38. cells/min was obtained. The proposed method is simple and robust for high-throughput single-cell analysis, allowing for analysis of cell population with considerable size to generate results with statistical significance. © 2010 Elsevier B.V.
Li L.J.,Hanshan Normal University
Applied Mechanics and Materials | Year: 2014
We present a bound for estimating the minimum-error probability of ambiguous discrimination between any m quantum operations. There are only Kraus-operators and a priori probabilities of the discriminated quantum operations in this bound, and which has nothing to do with the input states. To a certain extent, we generalize the bound on the minimum-error probability for ambiguous discrimination from mixed states to quantum operations. © (2014) Trans Tech Publications, Switzerland.
Zheng G.,Hanshan Normal University |
Liu Q.,Hanshan Normal University
Computers and Electrical Engineering | Year: 2013
Robustness is an important issue in Wireless Sensor Networks (WSNs). In this paper, two topology evolution models based on complex network theory are proposed. A bayesian game clustering algorithm is used to achieve a uniform clustering, and topology evolution is executed among cluster heads according to random walk. Residual energy, node fitness, node saturation and communication radius are considered in the processes of topology evolution. Simulation results show that network topologies formed by the models are more in line with the practical application of WSNs and have a good robustness in harsh environment. © 2013 Elsevier Ltd. All rights reserved.