关键词：
Laser beams;Light propagation;Negative refraction;Negative refractive index;Nonlinear optics;Split ring resonators
摘要：
We investigate quasi-steady-state (QSS) self-focusing in nonlinear left-handed metamaterials (NL-LHMs) theoretically. We have found that the negative refraction property of LHMs leads to the fact that the changes of the self-focusing distance and the focus appearing time with the spatial-focusing property of the input pulse are contrary to their counterparts for a conventional self-focusing medium. It is further shown that, as the convergence of the input pulse decreases, the first focus appears earlier and corresponds to smaller self-focusing distances, and that the focus moves more slowly at the smallest self-focusing distance, indicating a relatively higher risk of optical damage formation, in sharp contrast with a conventional self-focusing case. Besides, the divergent incidence cases have finite focus moving ranges.
作者机构：
[王勇献; 王正华; 贺细平; 姜彬] School of Computer, National University of Defense Technology, Changsha 410073, China;[贺细平] School of Information Science and Technology, Hunan Agricultural University, Changsha 410128, China
通讯机构：
School of Computer, National University of Defense Technology, China
摘要：
Rapeseed is one of the important oilseed crop species, and is worldwide the most important economically. The light seed colour in rapeseed is associated with improved oil, protein and fibre contents. But there are not reliable and efficient methods to measure seed colour, especially the single seed colour. Two transformations of RGB (red, green, and blue) colour space were used for two seed colour recognition methods, i.e., HSV (hue, saturation, and value) and nine colour model (NCM). Using these two colour space transformations, the performance of the common method on rapeseed colour recognition was compared with the major colour method. The common method obtained the colour recognition accuracy of 83.96% in single seed recognition and 92.72% in sample recognition. The major colour method obtained the colour recognition accuracy of 98.91% in single seed recognition and 100% in sample recognition. The major colour method combined with HSV and NCM colour space transformation proved to be a good approach for seed colour recognition of rapeseed using machine vision.
会议名称：
2008 International Conference on Machine Learning and Cybernetics(2008机器学习与控制论国际会议)
会议时间：
2008-07-12
会议地点：
昆明
会议论文集名称：
2008 International Conference on Machine Learning and Cybernetics(2008机器学习与控制论国际会议)论文集
关键词：
digital forensics;digital image forgery;tempering detection;passive-blind image forgery
摘要：
With the huge increasing use of digital photography, and the advent of high-performance commodity hardware and the presence of low-cost image editing softwares over the past few years, finding a credible method to detect digital image's authenticity and getting the result that which method the tampered image was applied to becomes a very valuable topic. In this paper, associating with the common forge methods, we propose the process of passive-blue detection of digital image's forging method, and then review the latest development of the passive-blind detection of image forging method, mainly include the detection of copy-move forgery, detection of blur forgery and detection of re-sample forgery.
作者机构：
[刘坚; 秦大力; 于德介] College of Mechanical and Auto Engineering, Hunan University, Changsha 410082, China;[秦大力] College of Information Science and Technology, Hunan Agricultural University, Changsha 410128, China
通讯机构：
College of Mechanical and Auto Engineering, Hunan University, China
作者机构：
[陈义明; 李舟军; 刘军万; 陈火旺] College of Computer, National University of Defense Technology, Changsha 410073, China;[刘军万] School of Computer Science, South Center University of Forest Science and Technology, Changsha 41000, China;[李舟军] School of Computer Science and Engineering, Beihang University, Beijing 100083, China;[陈义明] School of Information Science and Technology, Hunan Agricultural University, Changsha 410128, China
通讯机构：
College of Computer, National University of Defense Technology, China
作者机构：
[杨路明; 刘波] School of Information Science and Engineering, Central-South Univ., Changsha 410083, China;[邓云龙] The 3rd Xiangya Hospital, Central-South Univ., Changsha 410013, China;[刘波] Information Science and Technology Coll., Hunan Agricultural Univ., Changsha 410128, China
通讯机构：
School of Information Science and Engineering, Central-South Univ., China
摘要：
With the deeply research on intrusion detection techniques and the widely use of intrusion detection products, the study of evaluation techniques of intrusion detection systems became important. In the paper, relative works of the evaluation of intrusion detection systems was introduced. The primary aspects of intrusion detection systems in an evaluation were discussed. An evaluation system for intrusion detection systems was proposed. In the system, a supervisor module controls the whole system. The supervisor module schedules the traffic control module and the attack emulation module. The data in the evaluation environment are recorded and input to the evaluation module. The functions such as emulation of network traffic and host usage, emulation of attacks and evaluation report generation are implemented.
摘要：
The paper proposed modeling and simulation of distributed WLAN in OPNET. This model comprises of network model, node model and process model. Network model is the basic topology structure, node model describes the inside function module of all kinds of communication nodes, process model is used to make certain the management manner and management process of data. Moreover, we compare two primary channel allocation mechanisms of MAC level in IEEE 802.11 WLAN, Distributed Coordination Function (DCF) and Point Coordination Function (PCF).
会议论文集名称：
Lecture Notes in Engineering and Computer Science
关键词：
information audit;pattern matching;BM algorithms;network processor
摘要：
At present, network information audit system is almost based on text information filtering, Text categorization is the basic technology of text information filtering. Pattern matching algorithms are very important for the rule based information audit system. It directly influence the accuracy and real-time performance of the system. The KMP and BM algorithms are introduced in this paper. Research is carried out to improve the BM algorithm and a better BM algorithm is proposed According to the situation that the system characters group is bigger and that characters of the pat tern are less, the thesis puts forward an improved string-matching algorithm. The results of our experiments prove that it promotes the precision of text categorization.
关键词：
information audit;badness information;text character;Fuzzy neural network
摘要：
At Intelligent Methods for information audit system is hot spot in the field of network security, and application of pattern recognition and data mining in information audit system is world widely concerned and worldwide studying. As an important method of pattern recognition, Fuzzy neural network has the capability of self-organization, self-learning and generalization. Application of Fuzzy neural network in information audit system can not only identify the known badness information, but also can detect the new badness information and abnormal event.
作者机构：
[符国庆] School of Information Science and Technology, Hunan Agricultural University, Changsha 410128, China;[李晓争; 徐维祥] School of Traffic and Transportation, Beijing Jiaotong University, Beijing 100044, China
通讯机构：
[Fu, G.-Q.] S;School of Information Science and Technology, Hunan Agricultural University, China
