Journal of Shanghai University (english Edition) 

About: Journal of Shanghai University (english Edition) is an academic journal. The journal publishes majorly in the area(s): Nonlinear system & Boundary value problem. Over the lifetime, 1270 publications have been published receiving 3063 citations.

Principal manifolds and nonlinear dimensionality reduction via tangent space alignment

Abstract: We present a new algorithm for manifold learning and nonlinear dimensionality reduction. Based on a set of unorganized data points sampled with noise from a parameterized manifold, the local geometry of the manifold is learned by constructing an approximation for the tangent space at each point, and those tangent spaces are then aligned to give the global coordinates of the data points with respect to the underlying manifold. We also present an error analysis of our algorithm showing that reconstruction errors can be quite small in some cases. We illustrate our algorithm using curves and surfaces both in 2D/3D Euclidean spaces and higher dimensional Euclidean spaces. We also address several theoretical and algorithmic issues for further research and improvements.

TDOA-based Sybil attack detection scheme for wireless sensor networks

Abstract: As wireless sensor networks (WSN) are deployed in fire monitoring, object tracking applications, security emerges as a central requirement. A case that Sybil node illegitimately reports messages to the master node with multiple non-existent identities (ID) will cause harmful effects on decision-making or resource allocation in these applications. In this paper, we present an efficient and lightweight solution for Sybil attack detection based on the time difference of arrival (TDOA) between the source node and beacon nodes. This solution can detect the existence of Sybil attacks, and locate the Sybil nodes. We demonstrate efficiency of the solution through experiments. The experiments show that this solution can detect all Sybil attack cases without missing.

Generalized projective synchronization for the chaotic Lorenz system and the chaotic Chen system

Abstract: Protective synchronization and generalized projective synchronization have recently been observed in the coupled chaotic systems. In this paper, a new synchronization, called “generalized projective synchronization”, is reported in the chaotic Lorenz system and the chaotic Chen one.

Graft Modification of ZnO Nanoparticles with Silane Coupling Agent KH570 in Mixed Solvent

Abstract: The reaction of ZnO nanoparticles grafted with KH570 silane coupling agent was carried out in water-alcohol mixed solvent. Several characterization methods were applied to analyzing the results of surface modification such as Soxhlet extraction, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), thermogravimetry (TG), differential scanning calorimetry (DSC) and zeta potential (ζ). The results of FT-IR and TG-DSC show that the desired reaction chains have been covalently bonded on the surface of ZnO nanoparticles. Zetasizer results reveal that the maximal absolute value of ζ of the modified ZnO particles in acetone medium was 67.0 mV, which was much higher than that of the unmodified ZnO particles. So the surface of nanosized ZnO changed from hydrophilicity to hydrophobicity and the dispersity of ZnO nanoparticles were improved simultaneously. Finally, the mechanism of graft modification was discussed.

Influence of In-doping on resistivity of chemical bath deposited SnS films

Abstract: SnS and SnS:In films were deposited onto glass substrates by chemical bath technique The structure and surface morphology of the SnS:In films were studied by X-ray diffraction (XRD) and scanning electron microscope (SEM) respectively Energy dispersive spectroscopy (EDS) showed the existence of In in the films The undoped SnS film exhibited a rather high resistivity and InCl3 could reduce the resistivity of these films by two orders approximately The band gaps of the SnS and SnS:In films were evaluated from the optical transmission spectra