No abstract

In this paper, a new approach for non-invasive diagnosis of breast diseases is tested on the region of the breast without undue influence from the background and medically unnecessary parts of the images. We applied Wavelet packet analysis on the two-dimensional histogram matrices of a large number of breast images to generate the filter banks, namely sub-images. Each of 1250 resulting sub-images are used for computation of 32 two-dimensional histogram matrices. Then informative statistical features (e.g. skewness and kurtosis) are extracted from each matrix. The independent features, using 5-fold cross-validation protocol, are considered as the input sets of supervised classification. We observed that the proposed method improves the detection accuracy of Architectural Distortion disease compared to previous works and also is very effective for diagnosis of Spiculated Mass and MISC diseases.

Nowadays, sensor networks are one of the hottest scientific issues. A lot of research has been done to improve their efficiency. Wireless Sensor Networks (WSN) are applied as an important and efficient technology in many industries such as military operations, security systems, intelligent transportation systems, medics, agriculture, and many others. Key agreement is a challenging point in the security of these networks. Sensor nodes connect to each other using cryptography techniques, however, use of the classic key management techniques such as key distribution center is inefficient because of resource-constrained nature of the sensor nodes. This paper proposes a hierarchical multiple key agreement scheme. In the proposed scheme, two nodes can produce multiple session keys, just with only one run of the key agreement protocol by two nodes in the hierarchical system. As well as its efficiency, this new scheme is based on identity and non-interactive protocol. Being zero-knowledge proof is another advantage of the scheme.

No abstract

In the past, a large part of security requirements of wireless sensor networks (WSN) were fulfilled by symmetric cryptography systems. But, today by introduction of new needs in these networks and their security development, researchers of security and cryptography try to find new ways to increase efficiency and security of wireless sensor networks. Improving computational power of sensors used in wireless sensor networks made application of public key cryptography in WSN possible. Identity based cryptography is one important type of public key cryptography which using some bilinear functions called pairingfunctions was seriously applied. In this paper we will look at some researches done to find how to use pairings in wireless sensor networks.