This book is about the nature of intelligence, its causes and uses, and why it differs among people. Scientific psychology has much to say about intelligence, but unfortunately, much that has been said is misunderstood.

These are statements about the importance of intelligence for everyday life. They seem consistent with our own experiences, but they also could imply a cognitive elitism that many find uncomfortable. Nonetheless, compelling data support these statements and imply that everyday life can be seen as one long continuous intelligence test, and that the test is getting harder as modern life becomes more complex (Gottfredson, 1997; Gordon, 1997; Hunt, 1995).

In this chapter we describe methods used tomodel magnetic components in both the electricaland magnetic domains. Magnetic components such asinductors, coupled inductors, and transformers lieat the heart of most power electronic circuits.Multi-port components especially can exhibit quitecomplex behavior, and advancing the performance ofpower electronic circuits often relies onunderstanding and leveraging this behavior.

In analyzing motion, the first and most basic problem encountered is that of defining and dealing with the concepts of position, posture, and displacement. Since motion can be thought of as a series of displacements between successive positions of a point or postures of a body, it is important to understand exactly the meaning of the terms position and posture. Rules or conventions are established here to make the definitions precise.

The theory of machines and mechanisms is an applied science that allows us to understand the relationships between the geometry and motions of the parts of a machine, or mechanism, and the forces that produce these motions. The subject, and therefore this book, divides itself naturally into three parts. Part I, which includes Chapters 1–5, is concerned with mechanisms and the kinematics of mechanisms, which is the analysis of their motions. Part I lays the groundwork for Part II, comprising Chapters 6–10, in which we study methods of designing mechanisms. Finally, in Part III, which includes Chapters 11–16, we take up the study of kinetics, the time‑varying forces in machines and the resulting dynamic phenomena that must be considered in their design.

The concept of mass in linear motion was quite simple. However, the rotational analog, the moment of inertia, is comparatively complicated. In this chapter, we present a thorough introduction to the moment of inertia, and we develop the tools needed to compute this quantity for point masses, systems of discrete masses, and continuous rigid bodies about different axes of rotation. The chapter ends with some useful theorems that allow us to extend the application of these fundamental tools.

In previous chapters we have concentrated on the analysis of mechanisms where the dimensions of the links are known. By kinematic synthesis we mean the design or creation of a new mechanism to yield a desired set of motion characteristics. Because of the very large number of techniques available, this chapter presents only a few of the more useful approaches to show applications of the planar theory.1

A flywheel is an energy storage device. It absorbs mechanical energy by increasing its angular velocity and delivers energy by decreasing its angular velocity. Commonly, a flywheel is used to smooth the flow of energy between a power source and its load. If the load happens to be a punch press, for example, the actual punching operation requires energy for only a small fraction of its motion cycle. As another example, if the power source happens to be a two-cylinder, four-stroke engine, the engine delivers energy during only about half of its motion cycle. Other applications involve using flywheels to absorb braking energy and deliver acceleration energy for automobiles, or to act as energy-smoothing devices for electric utilities as well as solar- and wind-power-generating facilities. Electric railways have long used regenerative braking by absorbing braking energy back into power lines, but newly introduced and stronger materials now make the flywheel feasible for such purposes.

For testing the quality of wine produced in Southern France, you do not need to taste every grape in the vineyards of the region. You can taste samples from different regions to obtain a reasonable evaluation.

The three-terminal power devices introduced anddiscussed in Part III – the bipolar junctiontransistor, the power MOSFET, the insulated gatebipolar transistor, and the thyristor – eachrequires the application of a control terminalcurrent or voltage to cause the device to switch.So far we have assumed the necessary gate- orbase-drive waveforms are present. In this chapterwe address the detailed drive requirements ofthese devices and how the necessary drivewaveforms are created.

There are many power electronics applicationsin which one converts power between dc andhigh-frequency sinusoidal ac. In applications suchas induction heating, plasma generation,fluorescent lamp ballasts, electro-surgical tools,radio-frequency (RF) welding, and RFcommunications, the ac waveform is the converteroutput. In other applications, such as wirelesspower transfer and resonant dc/dc converters, ahigh-frequency sinusoid is an intermediatewaveform in the overall conversion process.