Browsing by Type "Book chapter"

Managers need to make informed choices about what to buy in order to meet priority needs and to avoid wasting limited resources. The procurement decision is a very difficult task since there exists a great variety of brands, vendors and equipment performances. In the present paper, we have developed a decision process for equipment procurement in which are used, in combination, a Multi-Criteria subjective weighting method SWARA (Step-wise Weight Assessment Ratio Analysis) for equipment evaluation weights, an adaptation of SAW (Simple Additive Weighting) for equipment performance and a new Multi-Objective optimization model for equipment procurement. TheMulti-Objective model considers several types of equipment, their costs and their performances. The model aims to be an aiding in the decision process of equipment procurement. Managers of health care systems need to find in their choices a compromise between the cost of procurement, brands' reputation, vendors' reputation and equipment performance. A numerical example for medical equipment procurement, based on sensors, is studied.

A Newton-type algorithm and line search strategies for solving generalized discrete-time algebraic Riccati equations are dealt with. The conceptual algorithm is presented, and its main computational steps are discussed. Evaluation of residuals and closed-loop matrices at each iteration, determination of the step size, and the use of line search with backtracking, are addressed in detail. Algorithmic and implementation issues taken into account in the developed solver are described. An extensive performance investigation on a large collection of examples has been performed, and the results are summarized. Both usual line search and line search with backtracking, and either identity or diagonal performance index matrices are considered. Difficult examples are included. The results often show significantly improved accuracy, measured in terms of normalized and relative residuals, in comparison with the state-of-the-art MATLAB function. The new solver is strongly recommended for improving the solutions computed by other solvers.

Space systems have become key enablers for a wide variety of applications on Earth through evolving capabilities in navigation, positioning, timing, data gathering and communications. These capabilities have become, in certain instances, critical to the functioning of critical infrastructure systems. These are interconnected sociotechnical systems which provide critical goods and services and whose destruction or disruption would cause significant loss of human life, material damage and other effects. The paper argues that space systems can provide a new category of critical infrastructures and highlights the differences between terrestrial and spaceborne systems from the perspective of the critical infrastructure protection framework.

Space systems are a key enabler for a wide variety of applications which have become critical to the functioning of modern societies. This chapter uses the Critical Infrastructure Protection framework to argue that space systems may constitute a new form of critical infrastructure, dubbed Critical Space Infrastructure, and traces the positive impact that such a perspective may have on space security governance. Critical Infrastructure Protection has developed a conceptual toolbox, as well as practical policy prescriptions, which may be of use to policy and decision-makers to increase resilience and meet future space security challenges.

The chapter promotes methods of feature design, under the hypothesis that the TF images are easy to compute, i.e. a high capacity of processing data is available. The next section considers the basic aspects of signal processing with data transforms, i.e. time-frequency and cosine transforms. From variously available time-frequency transforms (TFT), the Choi-Williams (CWT) transform is used, based on its good mathematical properties and fast algorithms of computation. Cosine Transform (CT) is also used based on his power to concentrate the information in its coefficients. The results of the experiments based on computer simulation using real data records are presented. Finally, is presented a synthesis of the main results in a qualitative way and some future steps to consider.

The main functional and support facilities offered by interactive environments and tools for Computer-Aided Control System Design (CACSD) and reference examples of such software systems are presented, from both a user and a developer perspective. The essential functions these environments should possess and requirements which should be satisfied are discussed. The importance of reliability and efficiency is highlighted, besides the desired friendliness and flexibility of the user interface. Widely used environments and software tools for CACSD, including MATLAB, Mathematica, Maple, and the SLICOT Library, serve as illustrative examples.

Linear and quadratic (Riccati) matrix equations are fundamental for systems and control theory and its numerous applications. Generalized or standard Sylvester and Lyapunov equations and generalized Riccati equations for continuous- and discrete-time systems are considered. Essential applications in control are mentioned. The main solvability conditions and properties of these equations, as well as state-of-the-art solution techniques, are summarized. The continuous progress in this area paves the way for further developments and extensions to more complex control problems.

Recent disputes have divided NATO and have served as a pretext for political confrontation between different Member States, spilling over into non-NATO issues. These disputes were centred on the idea, part technocratic and part moral, of National contribution to collective defence. The two percentage points of GDP that should be allocated have become a leitmotif of equitable burden sharing in the Alliance. This article argues that there are a number of different indicators being proposed that would better serve the interest of informing the public on the sharing of security burdens and details some of them.

This chapter is based on the discussions derived from the Advanced Research Workshop entitled “Critical Space Infrastructure: From Vulnerabilities and Threats to Resilience.” The recommendations provided regarding vulnerabilities, risks, and resilience of space critical infrastructures.

Current networks should provide disaster-resilience by coping with the possible failures and misbehaviours caused by massive natural or man-made disasters. This is necessary to keep a suitable level of Quality of Service after a disaster and to support the possible evacuation, rescue, assessment, and rescue operations within the affected area. Multiple possible methods and solutions can be put in place in a proactive and/or reactive manner to offer the required resilience degree. Among them, a proper routing algorithm can contribute to circumventing network elements damaged by the disaster or applying for spatial/temporal redundancy to guarantee effective communications. This chapter aims at presenting the main routing solutions to offer disaster-resilience communications, along with some related methods.