Stabilization of behaviours

In this paper we characterize the set of all restrictions on the behaviour of a plant that shape the characteristic polynomial of the closed-loop system. These control laws include both classical feedback laws and singular feedback laws. One of the results is the behavioural version of the Youla-Jabr-Bongiorno-Kucera-parameterization of all stabilizing control laws for a given plant. We also study robust stability, deriving the real and complex stability radius for systems described in kernel representation. Finally we characterize the set of all control laws that make the stability radius greater than or equal to some desired leve

The Kalman-Yakubovich-Popov lemma in a behavioural framework

The classical Kalman-Yakubovich-Popov Lemma provides a link between dissipativity of a system in state-space form and the solution to a linear matrix inequality. In this paper we derive the KYP Lemma for linear systems described by higher-order differential equations. The result is an LMI in terms of the original coefficients in which the dissipativity problem is posed. Subsequently we study the connection between dissipativity and spectral factorization of polynomial matrices. This enables us to derive a new algorithm for polynomial spectral factorization in terms of an LMI in the coefficients of a polynomial matrix

Quadratic performance of generalized first-order systems

In this note we formulate the Kalman-Yakubovic-Popov lemma for generalized first-order systems, both in continuous- and discrete-tim

The computer as means of communication for peer-review groups

In a scientific-writing course, 15 of 54 students used a review-supporting computer program, PREP-EDITOR (PREP), to communicate with their peers about drafts. In an exploratory study, 10 students were interviewed regularly: 5 used PREP and 5 met face-to-face to exchange comments on drafts. The study showed that use of PREP did not increase time spent on various writing activities. The PREP group reported a large number of computer-related problems, whereas the non-PREP group reported more difficulties with assignments and course organization. It appeared that the technology was omnipresent in PREP users' perception of the course. The system of computer-mediated peer review has many of the drawbacks of 'distance learning,' but because networks are increasingly used by collaborating authors, we should teach our students how to use them sensibly

Accessible Website Content Guidelines for Users with Intellectual Disabilities

Background: The W3C Web Accessibility Initiative has issued guidelines for making websites better and easier to access for people with various disabilities (W3C Web Accessibility Initiative guidelines 1999). - \ud Method: The usability of two versions of a website (a non-adapted site and a site that was adapted on the basis of easy-to-read guidelines) was tested with two groups of 20 participants. One group had intellectual disabilities but could read, the other group had no identified intellectual disabilities. In a 2 × 2 experimental design, it was investigated whether the easy-to-read website was indeed better accessible and usable for the participants with intellectual disabilities. - \ud Results: The adaptation of the website worked well for participants with intellectual disabilities. Users without identified intellectual disabilities were as effective with the adapted site as they were with the non-adapted site. - \ud Conclusion: The results form an empirical basis for recommendations about applying guidelines for easy-to-read text on websites for people with intellectual disabilities

Watch out for the preview: The effects of a preview on the usability of a Content Management System and on the user's confidence level

As time moves on, a trend crystallizes that sets new requirements on content management systems. The circle of users shifts from a small technically experienced group to a large network of inexperienced editors. Literature stresses that a higher need for usability is present if personnel with a low grade of human computer interaction expertise is using a system. But how can system designers accomplish a high level of usability? This study suggests a preview as an important factor for strengthening the usability (effectiveness, efficiency and satisfaction) of a content management system. The findings of this study support the hypothesis: the results showed that a preview enhances the userspsila satisfaction with the system. Moreover, the study shows that the userspsila confidence to be able to work with the system is an important factor; the results showed positive correlations between confidence and satisfaction and between confidence and effectiveness

Appropriate Financial Instruments for Public-Private Partnership to Boost Cross-Border Infrastructural Development-EU Experience

The member states of the European Union (EU) and the EU institutions have increasingly been using public-private partnerships (PPPs) to accelerate the development of (ambitious) trans-national infrastructure. This paper argues that in the EU (i) private sector partners remain risk-averse; and (ii) risk-pooling across a larger number of tax-payers tends to reduce the cost of risk to zero, making EU funds highly desirable and sought after for public infrastructure development. This paper argues that private equity has not been forthcoming to the extent that had been expected by those propagating this method of finance. In those instances where private non-publicly guaranteed resources have been used, the distribution of risks between public and private partners remained asymmetric, with public governmental bodies carrying the financial risks, which ultimately may become a contingent liability for the country’s public finances. However, EU and European Investment Bank (EIB) public funding is used not simply because the risks are spread more widely, but rather because EU rules and regulations for using such funds lead to better preparation of projects and greater efficiency gains in project implementation and delivery.public-private partnerships; trans-national infrastructure; european union institutions; european union; public infrastructure development