Encryption hardware is not available on most computer systems in use today. Despite this fact, there is no well accepted encryption function designed for software implementation - instead, hardware designs are emulated in software and the resulting performance loss is tolerated. The obvious solution is to design an encryption function for implementation in software. Such an encryption function is presented here - on a SUN 4/260 it can encrypt at 4 to 8 megabits per second. The combination of modern processor speeds and a faster algorithm make software encryption feasible in applications which previously would have required hardware. This will effectively reduce the cost and increase the availability of cryptographic protection.

{ Until recently, VLSI designers rarely considered yield issues when selecting a oorplan for a newly designed chip. This paper demonstrates that for large area VLSI chips, especially those that incorporate some fault tolerance, changes in the oorplan can aect the projected yield. We study several general oorplan structures, make some specic recommendations, and apply them to actual VLSI chips. We conclude that the oorplan of a chip can aect its projected yield in a non-negligible way, for chips with or without fault-tolerance. Index Terms { Clustering, defects, fault-tolerant ICs, oorplan, large-area ICs, yield. 1. Introduction In the process of designing a new chip, yield issues are rarely a factor in the choice of the oorplan. This is justied when the chip is relatively small and the defect distribution can be accurately described by either the Poisson or the compound Poisson yield models ([3]). In particular, in the most commonly used compound Poisson model, i.e., the ne...

The interaction of acid, PNA) vapor with liquid sulfuric acid surfaces was investigated for the acid contents from 50 to 70 wt % and over a temperature range from 205 to 230 K, using a fast flow-reactor coupled to a chemical ionization mass spectrometer. PNA was observed to be physically taken up by liquid sulfuric acid, without undergoing irreversible aqueous phase reactions, The measured coefficient was found to vary from about 0.2 on wt % to 0,06 on 70 % acid solution, From the dependent uptake, the quantity (that is the product of the law coefficient and the square root of the liquid-phase diffusion coefficient) obtained. The Henry's law volubility coefficient of PNA in sulfuric acid was by estimating the liquid-phase diffusion coefficient based on a cubic cell model. In general, y was found to increase with decreasing acid content and decreasing temperature. a constant partial pressure of 6.1X104 Torr, was determined to be M at 205 K and M at 222 K, as the acid content was...

The merits of Empirical Modelling (EM) principles and tools as a constructivist approach to computer science education are illustrated with reference to ways in which they have been used in teaching topics related to the standard computer science curriculum. The products of EM are interactive models – construals- that serve a sense-making role. Model-building proceeds in an incremental fashion through the construction of networks of definitions that reflect the observables, dependencies and agents associated with a current situation. The three principal case studies discussed (teaching bubblesort, solving Sudoku puzzles, and recognising groups from their abstract multiplication tables) highlight respects in which EM accounts for aspects of computing that cannot be effectively addressed by thinking primarily in terms of abstractions, procedures and mechanisms. The discussion of EM as a constructivist approach to computer science education is set in the context of an analysis of constructivism in computer science published by Ben-Ari in 2001. Reconciling EM's constructivist epistemology with this analysis involves recognising its pretensions to a broader view of computer science.

Abstract not found

Abstract: Vortices carrying truly non-Abelian flux moduli, which do not dynamically reduce to Abelian vortices, are found in the context of softly-broken N = 2 supersymmetric chromodynamics (SQCD). By tuning the bare quark masses appropriately we identify the vacuum in which the underlying SU(N) gauge group is partially broken to SU(n) ×SU(r) ×U(1)/�K, where K is the least common multiple of (n, r), and with N su(n) f = n and N su(r) f = r flavors of light quark multiplets. At much lower energies the gauge group is broken completely by the squark VEVs, and vortices develop which carry non-Abelian flux moduli CP n−1 ×CP r−1. For n> r we argue that the SU(n) fluctuations become strongly coupled and Abelianize, while leaving weakly fluctuating SU(r) flux moduli. This allows us to recognize the semi-classical origin of the light non-Abelian monopoles found earlier in the fully quantum-mechanical treatment of 4D SQCD. January