Waveforms for Gravitational Radiation from Cosmic String Loops

We obtain general formulae for the plus- and cross- polarized waveforms of gravitational radiation emitted by a cosmic string loop in transverse, traceless (synchronous, harmonic) gauge. These equations are then specialized to the case of piecewise linear loops, and it is shown that the general waveform for such a loop is a piecewise linear function. We give several simple examples of the waveforms from such loops. We also discuss the relation between the gravitational radiation by a smooth loop and by a piecewise linear approximation to it.Comment: 16 pages, 6 figures, Revte

Heave and pitch motions in shallow water including the effect of forward speed

The problem of small heave and pitch motions of a slender ship in shallow water including the effect of forward speed is analysed using the method of matched asymptotic expansions. Formulae valid to first order in slenderness are given for the added-mass and damping coefficients in terms of the frequency and subcritical Froude number

Keeping a Clean Heart (Chapter 7 of For Today: A Prayer When Life Gets Messy)

Excerpt: When I heard that some of the kids at school received an allowance, money their parents actually gave to them for no particular reason other than to do a few chores around the house, I could hardly believe it. It seemed too good to be true. I never received an allowance, and the idea of having some spending money of any kind was usually out of the question. Once in a while, my mother would give my brothers and me a quarter each to go to the municipal swimming pool if we hoed five rows of corn in the garden, but that was the extent of it. Honestly, we had a loving and supportive family life and there was always good food on the table and clean clothes in the closet, but there wasn\u27t any extra money for extravagances like allowances. We lived paycheck to paycheck, and my parents fretted far more than I knew about running out of money before the end of the month. So, I decided to earn my own spending money. At the age of thirteen, I became an independent businessman- peddling papers for the Saginaw News

Requirements for a Research-oriented IC Design System

Computer-aided design techniques for integrated circuits grown in an incremental way, responding to various perceived needs, so that today there are a number of useful programs for logic generation, simulation at various levels, test preparation, artwork generation and analysis (including design rule checking), and interactive graphical editing. While the design of many circuits has benefitted from these programs, when industry wants to produce a high-volume part, the design and layout are done manually, followed by digitizing and perhaps some graphic editing before it is converted to pattern generation format, leading to the often heard statement that computer-aided design of integrated circuits doesn't work. If progress is to be made, it seems clear that the entire design process has to be thought through in basic terms, and much more attention must be paid to the way in which computational techniques can complement the designer's abilities. Currently, it is appropriate to try to characterize the design process in abstract terms, so that implementation and technological biases don't cloud the view of a desired system. In this paper, we briefly describe the conversion of algorithms to masks at a very general level, and then describe several projects at MIT which aim to provide contributions to an integrated design system. It is emphasized that no complete system design exists now at MIT, and that we believe that general design considerations must constantly be tested by building (and rebuilding) the various subcomponents, the structure of which is guided by our view of the overall design process