El fraude empresarial: perspectiva internacional

Este trabajo analiza el fraude empresarial desde una perspectiva internacional. En los últimos años, ha estado muy presente en casos como el de Enron, WorldCom, Royal Ahold o PARMALAT, en los que se ven afectados la propia empresa, los trabajadores, el gobierno y, especialmente, los inversores, con pérdidas que pueden alcanzar millones de dólares. El fraude también afecta a la imagen de las empresas y en la motivación de los trabajadores, y además a menudo es causa de denuncias y penas de prisión. En función del tamaño de la empresa y del sector, la frecuencia con la que se cometen los actos fraudulentos y las pérdidas causadas varían. Asimismo, estos fraudes afectan a todas las regiones del mundo, aunque de manera desigual. Pero es en aquellas regiones más desarrolladas donde se le presta más atención al tema, y donde se han tomado numerosas medidas para intentar impedir estos actos ilícitos. Algunas de las más importantes son las propuestas por las Naciones Unidas: El Pacto Mundial y la Convención contra la Corrupción. También cabe destacar la Oficina Europea de Lucha Contra el Fraude, a nivel europeo, o la Foreign Corrupt Practices Act y la Ley Sarbanes-Oxley, en Estados Unidos. A pesar de estas medidas, en los últimos años el nivel de fraude ha aumentado.

Optical intrinsically fuzzy mathematical morphology for gray-scale image processing

Intrinsically fuzzy morphological erosion and dilation are extended to a total of eight operations that have been formulated in terms of a single morphological operation--biased dilation. Based on the spatial coding of a fuzzy variable, a bidirectional projection concept is proposed. Thus, fuzzy logic operations, arithmetic operations, gray-scale dilation, and erosion for the extended intrinsically fuzzy morphological operations can be included in a unified algorithm with only biased dilation and fuzzy logic operations. To execute this image algebra approach we present a cellular two-layer processing architecture that consists of a biased dilation processor and a fuzzy logic processor. (C) 1996 Optical Society of America

Morphological ordered gray-scale erosion for optical image processing

An ordered gray-scale erosion is suggested according to the definition of hit-miss transform. Instead of using three operations, two images, and two structuring elements, the developed operation requires only one operation and one structuring element, but with three gray-scale levels. Therefore, a union of the ordered gray-scale erosions with different structuring elements can constitute a simple image algebra to program any combined image processing function. An optical parallel ordered gray-scale erosion processor is developed based on the incoherent correlation in a single channel. Experimental results are also given for an edge detection and a pattern recognition. (C) 1998 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(98)00306-7].

Coma measurement using a PSM and transmission image sensor

As feature size decreases, especially with the use of resolution enhancement technique, requirements for the coma aberrations in the projection lenses of the lithographic tools have become extremely severe. So, fast and accurate in situ measurement of coma is necessary. In the present paper, we present a new method for characterizing the coma aberrations in the projection lens using a phase-shifting mask and a transmission image sensor. By measuring the image positions at multiple NA and partial coherence settings, we are able to extract the coma aberration. The simulation results show that the accuracy of coma measurement increases approximately 20% compared to the previous straightforward measurement technique. (c) 2005 Elsevier GmbH. All rights reserved.

Coma measurement of projection optics in lithographic tools based on relative image displacements at multiple illumination settings

In this paper, we propose a novel method for measuring the coma aberrations of lithographic projection optics based on relative image displacements at multiple illumination settings. The measurement accuracy of coma can be improved because the phase-shifting gratings are more sensitive to the aberrations than the binary gratings used in the TAMIS technique, and the impact of distortion on displacements of aerial image can be eliminated when the relative image displacements are measured. The PROLITH simulation results show that, the measurement accuracy of coma increases by more than 25% under conventional illumination, and the measurement accuracy of primary coma increases by more than 20% under annular illumination, compared with the TAMIS technique. (c) 2007 Optical Society of America.