This paper describes a stochastic jitter model for analyzing the performance and bit error rate (BER) of digital timing recovery circuits. The model uses parallel interconnected Markov chains to simulate the behavior of the system in response to both random and deterministic jitter. Unlike conventional Markov-chain models that require the system to be stationary, the parallel-chain model approximates deterministic changes in conditions with transitions between sub-chains. To verify the accuracy of the model, an analysis was performed on a digital delay-locked loop, and the results compared to measured data. The resulting transition probabilities and BER predicted by the proposed model are more than three orders of magnitude more accurate than those predicted by a conventional Markov-chain model.

As engineered systems that have traditionally been controlled centrally become more modular, distributed, and autonomous, techniques are needed to maintain control coordination among independent elements, often across a network with delays and bandwidth limitations. In particular, manufacturing systems may require tight coordination, or synchronization, among components acting on the same physical object. This paper addresses the problem of controller synchronization in such a system. We present an implementation of exact controller synchronization for independent controllers in a highly modular printing domain. Our approach, which allows networked controllers to join and leave a task dynamically, has produced excellent results on a high-speed printer prototype.

Document decomposition is a basic but crucial step for many document related applications. This paper proposes a novel approach to decompose document images into zones. It first generates overlapping zone hypotheses based on generic visual features. Then, each candidate zone is evaluated quantitatively by a learned generative zone model. We formulate the zone inference problem into a constrained optimization problem, so as to select an optimal set of non-overlapping zones that cover a given document image. The experimental results demonstrate that the proposed method is very robust to document structure variation and noise.