Possibility Of New Structures Research Articles

The Alvarez–Lohmann lens as a do-nothing machine

A do-nothing machine uses complex methods to convert an input pattern or function into an identical output pattern or function. They are of great interest because a selective modification somewhere within that machine can often accomplish useful results. Here, we start with the simplest possible optical system—a piece of glass split between the top and bottom by some simple or complex cut and rejoined perfectly. To light passing through, the cut does nothing. But, if we displace the top and bottom parts by some small amount, the combined system can serve as a variable thickness plate, a variable deflection angle prism, a variable focal length lens, etc. as first shown independently by Alvarez and Lohmann. This appears to be the first explanation of Alvarez–Lohmann lenses in such a simple way and it leads to the possibility of new structures not contemplated by either of the inventors.

A surge for solid state: Revitalization of the U.S. semiconductor industry may depend on supplying unconnected transistors and letting the buyer specify on-chip interconnections

The author maintains that the question of who will specify and design the chip system is at the heart of the major restructuring taking place within the semiconductor industry. If users specify how the foundry should connect transistors, semiconductor manufacturers can return to supplying chips on a more stable basis. After discussing the competitive challenge posed by Japan the author considers the adverse effect that job-hopping has had on the industry. He describes how the advent of silicon compilers and independent silicon foundries has opened the possibility of new structures for the semiconductor industry. The alternative ways in which chips can be defined, designed, supplied, and used can determine how the industry's basic activities are apportioned among users, designers, suppliers of computer-aided-design tools, and foundries. The four basic activities can be organized into 10 different structures of three basic types: foundry-centered, user-centered, and part-centered.