Dimitris Anastassiou

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In this paper, we present a nonlinear interpolation scheme for still image resolution enhancement. The algorithm is based on a source model emphasizing the visual integrity of detected edges and incorporates a novel edge fitting operator that has been developed for this application. A small neighborhood about each pixel in the low-resolution image is first(More)
Diseases such as cancer are often related to collaborative effects involving interactions of multiple genes within complex pathways, or to combinations of multiple SNPs. To understand the structure of such mechanisms, it is helpful to analyze genes in terms of the purely cooperative, as opposed to independent, nature of their contributions towards a(More)
We introduce the concept of Dynamic Rate Shaping, a technique to adapt the rate of compressed video bitstreams (MPEG-1, MPEG-2, H.261, as well as JPEG) to dynamically varying bit rate constraints. The approach provides an interface (or lter) between the encoder and the network, with which the encoder's output can be perfectly matched to the network's(More)
Packet switching of variable-bit-rate real-time video sources is a means for efficient sharing of communication resources while maintaining uniform picture quality. Performance analysis for the statistical multiplexing of such video sources is required as a first step towards assessing the feasibility of packet video. This paper extends our earlier work in(More)
We introduce the concept of Dynamic Rate Shaping, a technique to adapt the rate of compressed video bitstreams (MPEG-1, MPEG2, H.261, as well as JPEG) to dynamically varying rate (and delay) constraints. The approach provides an interface (or lter) between the encoder and the network, with which the encoder's output can be perfectly matched to the network's(More)
We describe and evaluate the performanceof the algorithms used in Columbia University’s “Xphone” multimedia communication system. The system assumes a “best-effort” operating system and network, and provides synchronized video/audio acquisition/playback (locally or across a network) with minimized and bounded end-to-end delay. Synchronization is achieved(More)
We present a unique FPGA that uses a mix of digital and large-signal analog computation for the simulation of gene regulatory networks. The prototype IC consists of a 4x5 array of configurable logic blocks along with programmable interconnect. It can simulate a network of pathways involving up to 20 genes and their associated proteins. The circuit design(More)
MOTIVATION The nematode C. elegans is an ideal model organism in which to investigate the biomolecular mechanisms underlying the connectivity of neurons, because synaptic connections are described in a comprehensive wiring diagram and methods for defining gene expression profiles of individual neurons are now available. RESULTS Here we present(More)