Selected reading from Treatise on Friendship

Course reading ebook, adapted by Ian D. Dunkle from Project Gutenberg’s Treatises on Friendship and Old Age, by Marcus Tullius Cicero, translated by E.S. Shuckburgh: http://www.gutenberg.org/ebooks/2808Cicero describes the necessary features, the value, and the limits of friendship through a short dialogue

Architectures for RF Frequency synthesizers

Frequency synthesizers are an essential building block of RF communication products. They can be found in traditional consumer products, in personal communication systems, and in optical communication equipment. Since frequency synthesizers are used in many different applications, different performance aspects may need to be considered in each case. The main body of the text describes a conceptual framework for analyzing the performance of PLL frequency synthesizers, and presents optimization procedures for the different performance aspects. The analysis of the PLL properties is performed with the use of the open-loop bandwidth and phase margin concepts, to enable the influence of higher-order poles to be taken into account from the beginning of the design process. The theoretical system analysis is complemented by descriptions of innovative system and building block architectures, by circuit implementations in bipolar and CMOS technologies, and by measurement results. Architectures for RF Frequency Synthesizers contains basic information for the beginner as well as in-depth knowledge for the experienced designer. It is widely illustrated with practical design examples used in industrial products.\ud Written for:\ud Electrical and electronic engineer

Signal processing for guided wave structural health monitoring

The importance of Structural Health Monitoring (SHM) in several industrial fields has been continuously growing in the last few years with the increasing need for the development of systems able to monitor continuously the integrity of complex structures. In order to be competitive with conventional non destructive evaluation techniques, SHM must be able to effectively detect the occurrence of damage in the structure, giving information regarding the damage location. Ultrasonic guided waves offer the possibility of inspecting large areas of structures from a small number of sensor positions. However, inspection of complex structures is difficult as the reflections from different features overlap. Therefore damage detection becomes an extremely challenging problem and robust signal processing is required in order to resolve strongly overlapping echoes. In our work we have considered at first the possibility of employing a deconvolution approach for enhancing the resolution of ultrasonic time traces and the potential and the limitations of this approach for reliable SHM applications have been shown. The effects of noise on the bandwidth of the typical signals in SHM and the effects of frequency dependent phase shifts are the main detrimental issues that strongly reduce the performance of deconvolution in SHM applications. The second part of this thesis is concerned with the evaluation of a subtraction approach for SHM when changes of environmental conditions are taken into account. Temperature changes result in imperfect subtraction even for an undamaged structure, since temperature changes modify the mechanical properties of the material and therefore the velocity of propagation of ultrasonic guided waves. Compensation techniques have previously been used effectively to overcome temperature effects, in order to reduce the residual in the subtraction. In this work the performance of temperature compensation techniques has been evaluated also in the presence of other detrimental effects, such as liquid loading and different temperature responses of materials in adhesive joints. Numerical simulations and experiments have been conducted and it has been shown that temperature compensation techniques can cope in principle with non temperature effects. It is concluded that subtraction approach represents a promising method for reliable Structural Health Monitoring. Nonetheless the feasibility of a subtraction approach for SHM depends on environmental conditions

What should be taught in courses on social ethics?

The purpose of this article is to discuss the concept and the content of courses on “social ethics”. I will present a dilemma that arises in the design of such courses. On the one hand, they may present versions of “applied ethics”; that is, courses in which moral theories are applied to moral and social problems. On the other hand, they may present generalised forms of “occupational ethics”, usually professional ethics, with some business ethics added to expand the range of the course. Is there, then, not some middle ground that is distinctively designated by the term “social ethics”? I will argue that there is such a ground. I will describe that ground as the ethics of “social practices”. I will then illustrate how this approach to the teaching of ethics may be carried out in five domains of social practice: professional ethics, commercial ethics, corporate ethics, governmental ethics, and ethics in the voluntary sector. My aim is to show that “social ethics” courses can have a clear rationale and systematic content