International Journal of Intelligent Engineering and Systems

5

Authors: Dennis Arturo Ludeña Romaña, Kenichi Sugitani, and Yasuo Musashi

The DNS query traffic from the inside and the outside of the campus network in a university was statistically investigated through January 1st, to July 31st, 2007. The following interesting results are obtained, as follows: (1) The unique source IP address-based entropy value is usually less than the unique DNS query keyword based one in the DNS query traffic from the campus network, however, the unique source IP address-based entropy value is greater than the unique DNS query keyword based one in the DNS query traffic from the outside of the campus network. (2) Two types of entropy changes were found in the unique source IP addresses- and the unique DNS resolution query keywords. In the both entropies, one is a parallel change, and another one is a symmetrical one. Although the latter change type can be conventionally observed in 2006, the former change type can recently observed in 2007. Therefore, it can be concluded that the recent spam bots send a lot of spam E-mails to the next victim PCs via the local vulnerable E-mail servers.

8

Authors: Kei Eguchi, Takahiro Inoue, Ichirou Oota, Hongbing Zhu, Fumio Ueno

For mobile applications, a switched-capacitor (SC) DC-DC converter which offers a 2x/ 1.5x/ 1x mode of operation is presented, and its properties are analyzed theoretically in this paper. Aimed at back-lighting applications, battery applications, etc., the proposed converter provides stepped-up/stepped-down voltages. Compared with the conventional approaches employing doubler circuits, the proposed converter can realize high efficiency and flexibility of output voltages. The validity of the proposed converter is confirmed by SPICE simulations and theoretical analyses. Concerning the power efficiency and the optimal duty factor, the confirmation result shows that the theoretical results correspond to the simulation results well. Furthermore, under the conditions that the input voltage Vin=3.7V, the output load RL, and the output voltage Vout=3.3 - 5.3V, the proposed converter can improve the power efficiency more than twice from that of the conventional circuit.

8

Authors: Rong Chen, Yongfeng Cao, Hong Sun, Wen Yang

Support vector machine is a new technique of machine learning developed from the middle of 1990s. There are two important things in the process of face recognition using SVM. One is the feature vectors extracted from face images, the other is the classifier we choose. Our approach optimizes traditional method from these two points. The adaptively weighted Fisherface purposes on a better feature extraction; the size condensing of training data is used to speed up the modeling of the SVMs; and binary tree structure SVMs is selected here to extend SVM to multi-class cases without much additional complexity. We do our experiments on ORL face database and get good recognition results. The accuracy of recognition results are compared to show the influence of the dimension of the Fisherface. At last, the benefit of adaptively weighted Fisherface is shown by a compare with the traditional Fisherface.