Cumulative size effects in electrical conductivity of thin semi-metal films

In the general framework of conduction models for monocrystalline and polycrystalline metal films, analytical expressions are derived for the electrical conductivity of semi-metal films. The existence of two cumulative size effects is thus predicted. These new equations agree with those previously derived in a special case of energy dependence of the relaxation time.     

Explicit formulation of delays in CMOS VLSI

An explicit formulation for the transient response of CMOS inverters is given, including load conditions and driving waveforms. Validation of the initial hypothesis is obtained through SPICE simulations. The results obtained show clear evidence of the influence of structural and parasitic parameters on propagation times, allowing fast optimisation of the data path.     

Effect of grain boundary scattering on the electrical conductivity of antimony films

By starting from the theory of Mayadas and Shatzkes, a model for the effect of grain boundaries on the electrical conductivity of an intrinsic semimetal is proposed. The influence of the size of crystallites on the electrical conductivity of polycrystalline antimony films is studied theoretically and experimentally.

Excellent agreement is obtained over a large temperature range (10–500 K) for various sizes of crystallites (100–2000 Å).     

Synchronous-mode evaluation of delays in CMOS structures

The extension of the explicit formulation of delays in CMOS VLSI to synchronous-mode evaluation allows the accurate evaluation of data path timing (few percent with respect to SPICE simulation) of general CMOS structures for all available input drive configurations, resulting in fast identification of timing problems. A validation of this method has been done using general series parallel networks. It was shown to be sufficiently accurate for resolving race problems. An implementation of the proposed algorithms has been conceived as a preprocessor for an event-driven switch simulator and it has been shown to be fast enough for use in VLSI timing analysis     

Consequence of electron scattering mechanisms on the conductivity of semi-metal films

A general expression for the resistivity of an infinitely thick polycrystalline semi-metal films is calculated starting from the Mayadas-Shatzkes conduction model. Good agreement with the experimental data related to antimony films is observed. Variations of the thermaly dependent term in conductivity with conductivity at low temperature cannot be neglected.     

News story segmentation in multiple modalities

In this paper, we describe an approach to segmenting news video based on the perceived shift in content using features spanning multiple modalities. We investigate a number of multimedia features, which serve as potential indicators of a change in story, in order to determine which are the most effective. The efficacy of our approach is demonstrated by the performance of our prototype, where a number of feature combinations demonstrate an up to 18% improvement in WindowDiff score compared to other state of the art story segmenters. In our investigation, there is no, one, clearly superior feature, rather the best segmentation occurs when there is synergy between multiple features. A further investigation into the effect on segmentation performance, while varying the number of training examples versus the number of features used, reveal that having better feature combinations is more important than having more training examples. Our work suggests that it is possible to train robust story segmenters for news video using only a handful of broadcasts, provided a good initial feature selection is made.     

The latent words language model

We present a new generative model of natural language, the latent words language model. This model uses a latent variable for every word in a text that represents synonyms or related words in the given context. We develop novel methods to train this model and to find the expected value of these latent variables for a given unseen text. The learned word similarities help to reduce the sparseness problems of traditional n-gram language models. We show that the model significantly outperforms interpolated Kneser–Ney smoothing and class-based language models on three different corpora. Furthermore the latent variables are useful features for information extraction. We show that both for semantic role labeling and word sense disambiguation, the performance of a supervised classifier increases when incorporating these variables as extra features. This improvement is especially large when using only a small annotated corpus for training.     

Delay propagation effect in transistor gates

Wide VLSI transistors suffer additional switching delays due to signal propagation when passing through the resistive gate polysilicide. We model and evaluate this resistive effect and define an analytical expression in terms of extra propagation term. This delay can be reduced by breaking up a single wide transistor into smaller transistors connected and driven in parallel. This work develops expressions for deciding how many parallel transistors should be employed so as to limit the additional delay caused by the resistive polysilicide to within desired bounds. The expressions are validated by comparing calculated delay results with those from HSPICE simulations     

Inductance effect in crosstalk prediction

Rapid progress in integrated circuit technology has led to an increase in switching speeds of digital circuits. This increase is the primary reason why inductance noise causes chips to fail. As a result, there is a growing interest in the inductance associated with on-chip signal lines. In this paper, we present the electromagnetic analysis we have followed in order to determine the accurate values of the R,L,C,G equivalent parameters from which a set of multiple coupled transmission lines could be modeled. We then determine the most critical parameters which make the inductance effect important and we propose a new analytical expression to accurately evaluate the crosstalk voltage.