Sheng G.,Ludong University |
Yang B.,Yantai Vocational College
International Journal of Mobile Computing and Multimedia Communications | Year: 2014
5With the growing awareness of the fraud case for digital images, the researchers have developed some forensic techniques that based on the intrinsic statistical history or trace left by the jpeg compression to determine an image's manipulation. Aiming at these forensic algorithms, special anti-forensic techniques was developed by removing footprints caused by jpeg compression. In this paper, the authors present an improved counterforensic scheme that based on parameter adjustment. The simulation shows that by using the proposed strategy and combining the chaotic theory, the scheme can erase the quantization artifacts perfectly, even when the compression factor Q ≤ 50 . Copyright © 2014, IGI Global.
Gong L.,Shanghai JiaoTong University |
Xi Y.,Yantai Vocational College |
Liu C.,Shanghai JiaoTong University
Mathematical Problems in Engineering | Year: 2013
Online monitoring of the instantaneous resistance variation during the A.C. resistance spot welding is of paramount importance for the weld quality control. On the basis of the welding transformer circuit model, a new method is proposed to measure the transformer primary-side signal for estimating the secondary-side resistance in each 1/4 cycle. The tailored computing system ensures that the measuring method possesses a real-time computational capacity with satisfying accuracy. Since the dynamic resistance cannot be represented via an explicit function with respect to measurable parameters from the primary side of the welding transformer, an offline trained embedded artificial neural network (ANN) successfully realizes the real-time implicit function calculation or estimation. A DSP-based resistance spot welding monitoring system is developed to perform ANN computation. Experimental results indicate that the proposed method is applicable for measuring the dynamic resistance in single-phase, half-wave controlled rectifier circuits. © 2013 Liang Gong et al.
Wang C.,Yantai Vocational College
ICCASM 2010 - 2010 International Conference on Computer Application and System Modeling, Proceedings | Year: 2010
In this paper, we describe our research into real-time configuration of e-commerce systems. We built an experimental multi-agent e-commerce system, in which agents will represent buyers, sellers, brokers and services of various kinds. The choice of system style has intrinsic appeal for demonstration and educational value, and also serves as a controlled tool for experimenting with alternative individual and group economic strategies, and for evaluating the effectiveness of e-commerce systems based on multi-agent. © 2010 IEEE.
Zhao C.-X.,Yantai Vocational College
Proceedings of International Conference on Information Systems for Crisis Response and Management, ISCRAM 2011 | Year: 2011
Complexity of landforms in China makes natural disasters happen constantly. Recently China has done much successful work in rescue of natural disasters. However, we still have a long way to go, as there still lays a great deal of problems in. We can establish lawful framework combining basic law with single laws, set up a unified and specialized agency for natural disaster management, develop a perfect system of natural disasters management and so forth. Through these suggestions, the author hopes that they might improve capability in dealing with natural disasters, reduce losses and bring to the public citizens so as to protect people's lives and property. Only in these ways, we can maintain the stability and development of society. © 2011 IEEE.
Liu Y.,Yantai University |
Yu H.,Yantai Vocational College |
Wu Y.,Yantai University
Journal of Computational and Theoretical Nanoscience | Year: 2016
Cognitive radio (CR) can solve the tough problem of limited spectrum resource for wireless communication. CR users (secondary users) need to detect if channels are occupied by licensed users (spectrum sensing) continuously, and employ the channel if it is free (licensed user do not user the channel). Spectrum sensing is very important for cognitive radio networks since it can prevent interference from other users with licensed users. This paper addresses the problem of cooperative sensing scheme based on hard fusion rules over different channels (AWGN, Rayleigh, Nakagami, and Log-Normal), and much attention is paid on which kind of fusion rules among three kinds of widely adopted rules (OR, AND, Majority) should be adopted in different situations. We first take average power as the test statistic, and give expressions of detection and false alarm probabilities for each cognitive radio user over AWGN, Rayleigh, Nakagami, and Log-normal channels, respectively. We then compare spectrum sensing performance of the three kinds of hard rules under different network contexts. OR rule has been used extensively as the proper fusion rule for cooperative spectrum sensing. However, via extensive experiments and theoretical analysis, we find that OR rule does not always perform best, and Majority rule is the appropriate fusion rule in many cases. The research is very important for selecting the proper fusion rule in different cognitive radio environments. © 2016 American Scientific Publishers All rights reserved.