作者机构：
[路建民; 李玉山; 丁同浩; 蒋冬初] Institute of Electronic CAD, Xidian University, Xi'an 710071, China;[蒋冬初] School of Electronic Engineering, Hunan City University, Yiyang 413000, China
通讯机构：
[Jiang, D.-C.] I;Institute of Electronic CAD, Xidian University, China
期刊：
International Journal of Applied Mathematics & Statistics,2013年45(15):404-412 ISSN：0973-1377
通讯作者：
Xiao, W.
作者机构：
[Xiao, Weichu] School of Communication and Electronic Engineering, Hunan City University, Yiyang 413002, Hunan, China;[Chen, Weihong] School of Information Science and Engineering, Hunan City University, Yiyang 413002, Hunan, China
通讯机构：
[Xiao, W.] S;School of Communication and Electronic Engineering, , Yiyang 413002, Hunan, China
关键词：
Image segmentation;Level set method;Local image information;Shape apriori
摘要：
We experimentally demonstrate the generation of ring-shaped beams using a plasma channel with Gaussian profile. The plasma channel is produced when an intense femtosecond pulse propagates in carbon disulfide. The refractive index of the plasma is similar to that of a graded-index lens. Due to the existence of critical plasma density, the beam from the He-Ne laser cannot pass through the center region of the plasma and is refracted in the periphery. The dark spot size of the ring-shaped beams can be controlled easily by a femtosecond pulse. We also show the propagation of ring-shaped beams in free space.
摘要：
Based on the Gram-Schmidt orthogonalization method utilized for pattern synthesis of linear array without constraints, side lobe levels constraints in certain angular region is proposed to implement pattern synthesis with broad nulls. The advantage of the simplified computation resulted from steering vector orthogonalization in unconstrained orthogonal approach is maintained, and the uniform or non-uniform linear array pattern synthesis can be realized by this method. The computational complexity of this method is smaller than iterative algorithm method's. The experimental results show that the side lobe levels constrained orthogonal approach can fulfill linear array broad null pattern synthesis with less computational efforts.
期刊：
Journal of Engineering Science and Technology Review,2013年6(3):122-127 ISSN：1791-9320
作者机构：
[GUO Sai-qiu] College of information science and Engineering, Hunan City University, Hunan 413000, China;[TANG Jing-min] Faculty of Information Engineering and Automation, Kunming University of Science and Technology, Yunnan 650500, China
期刊：
International Journal of Digital Content Technology and its Applications,2012年6(19):246-252 ISSN：1975-9339
通讯作者：
Zuo, W.(zwm123@126.com)
作者机构：
[Zuo, Weiming] Department of Computer Science, Hunan City University, Yiyang 413008, China
摘要：
Security support is mandatory for any communication networks. This paper proposed an improved Mutual Authentication Scheme in Multi-Hop Network, firstly, the algorithms method revised X.509 certificate based on ECC algorithm, then an enhanced mutual authentication flow was presented, which enhances the security and working efficiency of the mutual authentication in multi-hop WiMax system. The proposed scheme heightens the security and practicability of WiMax system, which has better referenced value to the improvement of IEEE 802.16e standards.
期刊：
International Journal of Digital Content Technology and its Applications,2012年6(22):222-230 ISSN：1975-9339
通讯作者：
Zhang, C.-Z.
作者机构：
[Zhang, Ci-Zhen] Pubic Courses Department, Xiangnan University, Chenzhou 423000, China;[Liu, Hean] Network Information Center, Hunan City University, Yiyang 413000, China
摘要：
For weaknesses of a fixed structure and no personalization at the current remote education website, this paper uses the Web mining technology, extracts the server Web log of the website as the data source, finds the expected location of the target pages from the user access transaction sequences by using FEL and CRLL algorithm and generates the recommended link list according to the rule of minimal "Back" time, so the website can be changed according to the certain rule. This paper constructs a personalization Web system to predict Web page access and recommend contents by using user clustering, page clustering, frequent access path discovery and user group similarity.
期刊：
Journal of Convergence Information Technology,2012年7(12):438-444 ISSN：1975-9320
通讯作者：
Zhou, J.(zhoujiancun101@126.com)
作者机构：
[Zhou, Jiancun] School of Information Science and Engineering, Hunan city University, Yiyang, China
摘要：
This paper studies accurate intrusion detection of the multiple mutation networks. The network intrusion viruses may mutate multiple times in a short period, it makes the network intrusion features deviate from the original features much and mutate dramatically. The traditional algorithm detects intrusion based on the original features of the network intrusion. The dramatic changes of the original features will reduce the accuracy rate of the network intrusion. This paper proposes a detection method for multiple mutation network intrusion based on the artificial immune algorithm. This method establishes a dynamic change equation of the network intrusion features, gets the crossing point distribution of the network intrusion features, updates the network intrusion feature database and selects network intrusion features from the database, so it overcomes the weaknesses of the traditional algorithm. The test indicates that this algorithm can avoid the defect of the network intrusion feature mutation and improves accuracy rate of the network intrusion detection.
期刊：
International Journal of Digital Content Technology and its Applications,2012年6(19):239-245 ISSN：1975-9339
通讯作者：
Bai, N.(realbain@gmail.com)
作者机构：
[Zhou, Libo] Network Information Center, Hunan City University, Yiyang, 413000, Hunan, China;[Bai, Na] National Mobile Communication Research Laboratory, Southeast University, China
摘要：
The research of image recognition's high-speed processing problems is conducted to improve the image's practical processing capabilities. Most of the existing image recognition system is composed on the basis of ordinary CPU machine or DSP, which has the defects of limited calculation bandwidth, low efficiency, resource wasting and poor flexibility. The reason is that, due to the commonly used computer hardware design's lack in image recognition algorithm, image processing algorithm's data is low in number and has Bit Boolean operators, convolution and so on. All of these make it inappropriate to use multi-digit computer system. To solve the above problem, an image recognition processing system based on FPGA is formulated on the basis of matching algorithm. It is the development and improvement of matching algorithm. The system rapidly completes matching algorithm and the process, ensures the high-speed identification of image recognition system. The simulation results show that the proposed method can effectively improve the speed of image recognition and greatly reduce hardware costs.
作者：
Jiasheng, Li;Weichu, Xiao;Xuejun, Zhang;Wenguo, Li;Saichun, Hu
期刊：
Information Technology Journal,2012年11(11):1632-1637 ISSN：1812-5638
通讯作者：
Jiasheng, L.
作者机构：
[Xuejun, Zhang; Wenguo, Li; Jiasheng, Li; Saichun, Hu; Weichu, Xiao] College of Communication and Electronic Engineering, Hunan City University, Yiyang, Hunan, 413000, China
通讯机构：
[Jiasheng, L.] C;College of Communication and Electronic Engineering, Hunan City University, China
期刊：
International Journal of Digital Content Technology and its Applications,2012年6(15):475-482 ISSN：1975-9339
通讯作者：
Chen, W.(hnyycwm@163.com)
作者机构：
[Chen, Weimin] College of Information Science and Engineering, Hunan City University, 413000, Hunan Yiyang, China
摘要：
Recently, Yang et al. proposed an security of improvement on Tseng et al.'s protected password transmission scheme to withstand replay attacks, guessing attacks, server spoofing and modification attacks. However, as we will point out in this paper, any adversary can intercept the request for changing the password sent by a legal user and replace the new password with the original password. thus, these protocols are vulnerable to denial of service attacks. Furthermore, we extend their work so that the improvement protocols are more secure than previous ones.
期刊：
Advances in Information Sciences and Services,2012年4(14):53-61 ISSN：1976-3700
通讯作者：
Jin, H.(Jinhuixia1980@163.com)
作者机构：
[Jin, Huixia] Department of Physics and Telecom, Engineering Hunan City University, China;[Deng, Xiaojun] College of Computer and Communication, Hunan University of Technology, Zhuzhou, 412008, China;[Zuo, Weiming] Department of Computer Science, Hunan City University, Yiyang 413000, China
通讯机构：
[Jin, H.] D;Department of Physics and Telecom, China
摘要：
Magnetic resonance imaging is a new imaging technology based on the hydrogen's magnetic resonance feature. Gradient module should have high calculation speed and accuracy to complete massive computation work including rotation transform, eddy compensation and shimming in a very short time. We make a deep exploration into the gradient module from its function, real-time and accuracy requirements. Then, we propose and realize a novel gradient module based on high performance DSP. Experiments indicate that the gradient module we designed satisfies the function, real-time and accuracy requirements. It provides a practical gradient module solution for the development of digital Spectrometer.
