Donggang, China
Donggang, China

Zhaoqing University is a public university based in the Duanzhou District of the prefecture level city of Zhaoqing, Guangdong Province, China. Zhaoqing University is a provincial comprehensive university which enrolls students on four-year degree programmes. Wikipedia.

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Zhang Z.,Zhaoqing University | Chen L.,Sun Yat Sen University
China Economic Review | Year: 2014

The ratio, Penn effect and behavioral equilibrium exchange rate (BEER) are used to assess the level of the bilateral real exchange rate of the Chinese RMB against the US dollar in 1980-2012. The statistical indexes and economic meaning indicate that the findings from the BEER and ratio models are more reasonable. Based on the two models, the RMB was overvalued by about 10-20% in 2011-2012. Given the already overvalued currency and the not-ideal economic situation, China should (1) control its excessive money supply to suppress the purchasing power parity rate appreciation and (2) keep the level of the nominal exchange rate stable. © 2014 Elsevier Inc.

Liu J.J.,Zhaoqing University
2016 IEEE International Conference on Information and Automation, IEEE ICIA 2016 | Year: 2016

Nowadays, 3D laser scanners find a wide range of applications such as object measurement, orthotics and prosthetics, reverse engineering and prototyping, quality control, part inspection and documentation of cultural artifacts. 3D scanning is a fast and accurate method of putting physical measurements of an object onto computer. Theoretically, this technology can be extended for the development of 3D laser scanners that work in water. Laser stripe extraction methods is one of the most important step in laser scanning system. However, most of current laser stripe extraction methods designed to work in air, which is virtually inevitable in underwater conditions. This paper firstly describes and addresses some of the main issues in underwater 3D laser scanners development including water index, waterproof housing design, signal transmission and laser stripe saturation which are crucial for the applications such as underwater oil and gas inspection. This work also proposed an effortless process for straight laser stripe generation. Finally, a series of experiments based on real and artificial images are performed to evaluate the proposed procedure and the common laser peak detections performance in underwater scanning environment. © 2016 IEEE.

Wan L.,Wuhan Textile University | Zhou Q.,Zhaoqing University
Nonlinear Analysis: Real World Applications | Year: 2011

This paper investigates the attractor and ultimate boundedness for stochastic cellular neural networks with delays. By employing the Lyapunov method and a Lasalle-type theorem, novel results and sufficient criteria on the attractor and ultimate boundedness are obtained. © 2011 Elsevier Ltd. All rights reserved.

Unusual trimeric and tetrameric water clusters have been observed in a complex of [Cu(DBA)(phen) 2·(H 2O) 4·(NO 3)] (1), (HDBA = benzilic acid, phen = 1,10-phenanthroline), which was prepared under solvothermal conditions and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), UV-Vis spectroscopy, powder X-ray diffraction and single-crystal X-ray diffraction. In 1, a butterfly-like water-nitrate trimer formed by two water molecules and one nitrate anion, as well as a cyclic tetrameric water cluster are observed. The uncoordinated carboxylate oxygen atoms of DBA ligands, water molecules and nitrate anions interact via hydrogen bonds and extend 1 into a water-anion-cation tape, which in turn join to form a double water-anion-cation tape via π···π stacking interactions involving neighboring pyridyl and phenyl groups of DBA ligands. © 2012 Elsevier B.V. All rights reserved.

Peng S.,Zhaoqing University | Yu S.,Deakin University | Yang A.,Guangdong University of foreign Studies
IEEE Communications Surveys and Tutorials | Year: 2014

Smartphones are pervasively used in society, and have been both the target and victim of malware writers. Motivated by the significant threat that presents to legitimate users, we survey the current smartphone malware status and their propagation models. The content of this paper is presented in two parts. In the first part, we review the short history of mobile malware evolution since 2004, and then list the classes of mobile malware and their infection vectors. At the end of the first part, we enumerate the possible damage caused by smartphone malware. In the second part, we focus on smartphone malware propagation modeling. In order to understand the propagation behavior of smartphone malware, we recall generic epidemic models as a foundation for further exploration. We then extensively survey the smartphone malware propagation models. At the end of this paper, we highlight issues of the current smartphone malware propagation models and discuss possible future trends based on our understanding of this topic. © © 2014 IEEE.

Xu S.,Zhaoqing University
Nonlinear Analysis: Real World Applications | Year: 2011

In this paper we study a free boundary problem modeling the growth of nonnecrotic tumors with time delays in proliferation. The establishment of the model is based on the diffusion of nutrient and mass conservation for the two processes: proliferation and apoptosis (cell death due to aging). It is assumed that the process of proliferation is delayed compared to apoptosis. By Lp theory of parabolic equations and the Banach fixed point theorem, under some conditions we prove the existence and uniqueness of a local solution and apply the continuation method to get the existence and uniqueness of a global solution. We also prove that in case c (the ratio of the nutrient diffusion time scale to the tumor growth (e.g. tumor doubling) time scale) is sufficiently small, the volume of the tumor cannot expand unlimitedly. © 2011 Elsevier Ltd. All rights reserved.

Peng S.,Zhaoqing University | Wang G.,Central South University | Yu S.,Deakin University
Journal of Computer and System Sciences | Year: 2013

Smartphones combine the communication capabilities of cellphones and the functions of PDA (personal digital assistant), which enable us to access a large variety of ubiquitous services, such as surfing the web, sending/receiving emails, MMS, and online shopping. However, the availability of these services provided by smartphones increases the vulnerability to worm attacks. In addition, modeling on worm propagation in smartphones is particularly challenging because it is difficult to piece together dynamics from pair-wise device interactions. To characterize the propagation dynamics of worms in smartphones, we propose an efficient worm propagation modeling scheme using a two-dimensional cellular automata based on the epidemic theory. A set of suitable local transition rules is designed for the two-dimensional cellular automata in this scheme. Moreover, this scheme integrates an infection factor to evaluate the spread degree of infected nodes, and a resistance factor to evaluate the degree that susceptible nodes resist. Five classes of epidemic states are considered: susceptible, exposed, infected, diagnosed, and recovered. We explore a strategy for simulating the dynamics of worm propagation process from a single node to the entire network. The effectiveness and rationality of the proposed model have been validated through extensive simulations. © 2012 Elsevier Inc.

Wang H.-w.,Zhaoqing University | Liu Y.-q.,Zhaoqing University
Food Chemistry | Year: 2010

Trace and toxic elements in Paris polyphylla samples were determined by flame and graphite furnace atomic absorption spectrometry following microwave-assisted acid digestion, based on a mixture of nitric acid and hydrogen peroxide. The whole procedure, including sample preparation, digestion and measurements, was successfully validated against CRM GBW07603 (bush twigs and leaves). In order to get a better insight into the elemental patterns, common chemometric approaches to data evaluation, such as principal component analysis (PCA) and hierarchical cluster analysis (HCA), were used as classification techniques. Five significant groups classified by PCA were attributed partly to significant influential sources. HCA revealed five groups of P. polyphylla samples based on their trace and toxic element concentrations. © 2010 Elsevier Ltd. All rights reserved.

Peng S.,Zhaoqing University
Applied Mechanics and Materials | Year: 2013

Smartphones providing services like SMS/MMS, emails, online banking, and other applications, are becoming an integral part of our everyday lives. However, the availability of these services and applications provided by smartphones makes them a target for malicious attackers to propagate malware and perform other malicious attacks. To restrain malware propagation, the research advancement of malware containment is summarized in this paper. We provide an overview on malware, which includes the evolution of mobile malware, related concept, infection vectors, and risks. The typical malware containment models are selected to discuss in detail. At last, the current problems and challenges in this field for future work are proposed. This paper indicates that diversity and complexity of mobile malware pose great challenges in modeling malware containment. © (2013) Trans Tech Publications, Switzerland.

Xu S.,Zhaoqing University
Nonlinear Analysis: Real World Applications | Year: 2010

In this paper, a free boundary problem modeling tumor growth under the direct effect of an inhibitor with time delays is studied. The delays represent the time taken for cells to undergo mitosis. Nonnegativity of solutions, the existence of the stationary solutions and their asymptomatic behavior are studied. The results show that when the inhibitor is large, and the initial tumor is not too large, the tumor will disappear. If however, the initial tumor is large enough, then it will grow. When the inhibitor is not as large, the growth of the tumor is determined by the size of the nutrients and whether the initial tumor is large or not. When the inhibitor is smaller, the tumor will grow no matter if the initial tumor is large or not. © 2008 Elsevier Ltd. All rights reserved.

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