The authors propose a new solution to the watermarking of images. This approach uses Independent Component Analysis (ICA) to project the image into a basis with its components as statistically independent as possible. The watermark is then introduced in this representation of the space. Thus, the change of basis is the key of the steganography problem. The algorithm applied to the fragile watermarking problem locates any change in the image since it also applies to the watermark. The problem of robust watermarking is also addressed from this new point of view. Some results are included to illustrate the method.

--The paper presents a competence-based instructional design system and a way to provide a personalization of navigation in the course content. The navigation aid tool builds on the competence graph and the student model, which includes the elements of uncertainty in the assessment of students. An individualized navigation graph is constructed for each student, suggesting the competences the student is more prepared to study. We use fuzzy set theory for dealing with uncertainty. The marks of the assessment tests are transformed into linguistic terms and used for assigning values to linguistic variables. For each competence, the level of difficulty and the level of knowing its prerequisites are calculated based on the assessment marks. Using these linguistic variables and approximate reasoning (fuzzy IF-THEN rules), a crisp category is assigned to each competence regarding its level of recommendation.Index Terms--Educational systems, fuzzy logic, personalized navigation, user modelling.

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The advent of numerous technological platforms for genome sequencing has led to increasing understanding and construction of metabolic networks. A popular system engineering strategy is used to analyze microbial metabolic networks is flux balance analysis (FBA). In recent times, there has been a lot of interest in the study of the metabolic network dynamics when genes are overexpressed in the system. Herein, an optimization framework, which employs dynamic flux balance analysis (DFBA) is proposed for predicting ethanol concentration profiles in glycerol fermentations using Escherichia coli. In silico results were experimentally validated by overexpressing alcohol/acetaldehyde dehydrogenase adhE, pyruvate kinase pykF, pyruvate formate-lyase pflB and isoleucine-valine enzymes ilvC and llvL.