Teaching integrated circuit and semiconductor device design in New Zealand: the University of Canterbury approach

Teaching the practical aspects of device and chip design in New Zealand presents many problems, including high manufacturing costs, long lead times, and the lack of local industry strength. Nonetheless, it is possible to overcome these issues. This paper describes the courses in these areas at the University of Canterbury, including a practical IC design project that has been running successfully for the past four years. The IC design project takes final year students through a full custom design using modern design tools and fabrication processes. The design is quite straightforward — a 4-bit arithmetic logic unit — but it emphasises the importance of design, simulation and testing. The final circuits contain a few hundred transistors, so good practice is essential. Twelve designs are integrated on to a single chip to keep costs down, and individual designs are addressed via multiplexers. The designs are fabricated using a 0.5 micron process, accessed through a multi-project vendor (MOSIS). Getting chips back from a manufacturer is significantly more motivating for the students than just performing a paper design

Non-monotonic variation with salt concentration of the second virial coefficient in protein solutions

The osmotic virial coefficient $B_2$ of globular protein solutions is calculated as a function of added salt concentration at fixed pH by computer simulations of the ``primitive model''. The salt and counter-ions as well as a discrete charge pattern on the protein surface are explicitly incorporated. For parameters roughly corresponding to lysozyme, we find that $B_2$ first decreases with added salt concentration up to a threshold concentration, then increases to a maximum, and then decreases again upon further raising the ionic strength. Our studies demonstrate that the existence of a discrete charge pattern on the protein surface profoundly influences the effective interactions and that non-linear Poisson Boltzmann and Derjaguin-Landau-Verwey-Overbeek (DLVO) theory fail for large ionic strength. The observed non-monotonicity of $B_2$ is compared to experiments. Implications for protein crystallization are discussed.Comment: 43 pages, including 17 figure

Cointegration analysis with state space models

Abstract: This paper presents and exemplifies results developed for cointegration analysis with state space models by Bauer and Wagner in a series of papers. Unit root processes, cointegration and polynomial cointegration are defined. Based upon these definitions the major part of the paper discusses how state space models, which are equivalent to VARMA models, can be fruitfully employed for cointegration analysis. By means of detailing the cases most relevant for empirical applications, the I(1), MFI(1) and I(2) cases, a canonical representation is developed and thereafter some available statistical results are briefly mentioned.