Performance modelling is concerned with the capture and analysis of the dynamic behaviour of computer and communication systems. The size and complexity of many modern systems result in large, complex models. A compositional approach decomposes the system into subsystems that are smaller and more

Abstract- Shape modeling is an important constituent of computer vision as well as computer graphics research. Shape models aid the tasks of object representation and recognition. This paper presents a new approach to shape modeling which re-tains some of the attractive features of existing methods

The experimental evidence accumulated over the past 20 years indicates that text indexing systems based on the assignment of appropriately weighted single terms produce retrieval results that are superior to those obtainable with other more elaborate text representations. These results depend crucially on the choice of effective term-weighting systems. This article summarizes the insights gained in automatic term weighting, and provides baseline single-term-indexing models with which other more elaborate content analysis procedures can be compared.

Distributed computing systems are being built and used more and more frequently. This distributod computing revolution makes the reliability of distributed systems an important concern. It is fairly well-understood how to connect hardware so that most components can continue to work when others are broken, and thus increase the reliability of a system as a whole. This report addressos the issue of providing software for reliable distributed systems. In particular, we examine how to program a system so that the software continues to work in tho face of a variety of failures of parts of the system. The design presented

Data augmentation and Gibbs sampling are two closely related, sampling-based approaches to the calculation of posterior moments. The fact that each produces a sample whose constituents are neither independent nor identically distributed complicates the assessment of convergence and numerical

This paper discusses the prevalence of Silicon Valley–style localiza-tions of individual manufacturing industries in the United States. A model in which localized industry-specific spillovers, natural ad-vantages, and pure random chance all contribute to geographic concentration is used to develop a test for whether observed levels of concentration are greater than would be expected to arise ran-domly and to motivate new indices of geographic concentration and of coagglomeration. The proposed indices control for differ-ences in the size distribution of plants and for differences in the size of the geographic areas for which data are available. As a conse-quence, comparisons of the degree of geographic concentration across industries can be made with more confidence. Our empiri-cal results provide a strong reaffirmation of the previous wisdom in that we find almost all industries to be somewhat localized. In many industries, however, the degree of localization is slight. We explore the nature of agglomerative forces in describing patterns of concentration, the geographic scope of localization, and the coagglomeration of related industries and of industries with strong upstream-downstream ties.

class of erasure codes that for large block sizes are orders of magnitude faster than standard erasure codes. We provide performance measurements that demonstrate the feasibility of our approach and discuss the design, implementation and performance of an experimental system.

Probabilistic inference is an attractive approach to uncertain reasoning and empirical learning in artificial intelligence. Computational difficulties arise, however, because probabilistic models with the necessary realism and flexibility lead to complex distributions over high-dimensional spaces

This is the manuscript that was published, with only minor copy-editing alterations, as: Haidt, J. (2001). The emotional dog and its rational tail: A social intuitionist approach to moral judgment. Psychological Review. 108, 814-834 Copyright 2001, American Psychological Association To obtain a

the data is aggregated and stored for offline querying and analysis. This approach has two major drawbacks. First, the user cannot change the behavior of the system on the fly. Second, conservation of battery power is a major design factor, but a central system cannot make use of in-network programming