A security system based on human iris identification using wavelet transform

A security system based on the recognition of the iris of human eyes using the wavelet transform is presented. The zero-crossings of the wavelet transform are used to extract the unique features obtained from the grey-level profiles of the iris. The recognition process is performed in two stages. The first stage consists of building a one-dimensional representation of the grey-level profiles of the iris, followed by obtaining the wavelet transform zerocrossings of the resulting representation. The second stage is the matching procedure for iris recognition. The proposed approach uses only a few selected intermediate resolution levels for matching, thus making it computationally efficient as well as less sensitive to noise and quantisation errors. A normalisation process is implemented to compensate for size variations due to the possible changes in the camera-to-face distance. The technique has been tested on real images in both noise-free and noisy conditions. The technique is being investigated for real-time implementation, as a stand-alone system, for access control to high-security areas.

吝啬语义信任协商

自动信任协商是通过数字证书的交互披露在陌生实体间建立信任的过程,现有的自动信任协商框架要求主体出示完整属性证书来证明自己满足对方资源披露策略中的身份断言约束条件,导致了属性证书中身份信息过度披露问题.该文中作者提出一种通过交换DL-TNL语义身份断言来建立信任关系的吝啬语义信任协商框架,避免了完整属性证书的直接出示,减少信任建立过程中身份信息被披露的程度,并提出一种正确、完备且有效的吝啬语义信任协商策略.在该策略下,交易双方的协商引擎可以快速有效地从由身份断言权威签发的包含多个DL-TNL语义身份断言的身份断言证书中,自动计算出批露最少信息且符合对方策略的身份断言集进行出示,以最大限度地减少信任建立过程中被披露的身份信息,并保证理论上存在成功可能性时,使用该策略必然可以有效地帮助主体最终获得网络资源的访问权限.有关该策略完备性和正确性的证明以及策略实施中所使用的符合性检测算法的实现和分析均在文中给出.

Cuatro décadas en Economía de la Educación.

Resumen tomado del autor. Resumen en castellano e inglés. Notas a pie de página. Este artículo se incluye en el monográfico 'Didácticas específicas'

Indoor radon measurements in six Latin American countries

Most of the natural radiation dose to man comes from radon gas and its progeny. Several countries have established national institutions and national programs in charge of the study of radon and its connection with lung cancer risk and public health. In this paper an indoor radon measurements in Latin American countries is presented. The participants in this work were from Argentina, Brazil, Ecuador, Mexico, Peru and Venezuela. Many different techniques are used in this common effort, and the indoor radon levels in specific locations in each of the participant countries are presented.

Emile Prudent, Ganzfigurbildnis

Signatur des Originals: S 36/F01561