Abstract
Line scratches and blotches are two of the most common and annoying artifacts of image sequences. A digital restoration chain for the removal of these artifacts was conceived and implemented. The basic elements of the chain are the digital encoder, the artifact generator, tile artifact detectors, the interpolators and the quality measurer. The digital encoder has the mission to convert analogue sequences into digital ones and, if necessary, to make a format conversion. The artifact generator allows quantitative and qualitative tests of the restoration algorithms. If we have access to the original non-degraded sequence we can add, in a controlled way, artifacts with the generator, and then measure efficiently the quality of the restoration algorithms, since we have the original, the degraded and the restored sequences to compare. In a real restoration process, the degraded sequence is directly applied to the artifact detector. The artifact detector finds the degraded regions in tile image and, somehow, marks them. Tile interpolator replaces the marked degraded pixels with others that are the result of an interpolation algorithm. Finally, the quality measurer rates the quality of the restored sequence.

Abstract
We consider the performance of a hybrid radio-over-fiber distribution system with a remote phase-locked loop (PLL) providing the local oscillator for upconversion to millimeter (mm)-wave frequencies. The reference signal for the PLL is transmitted together with digitally modulated subcarriers over a fiber link, allowing centralization of radio processing. Through analysis and simulation, we identify the relationship between the phase noise requirement for the PLL and the data capacity of the fiber link. For a practical link, we provide an upper limit on system capacity for transmission of 16 quadrature amplitude modulation (QAM) subcarriers.

Abstract
The nesting problem consists of defining the cutting plan of a piece of raw material in smaller irregular shapes, and has applications in the apparel and footwear industries. Due to its NP-hard nature, the optimal solution can only be guaranteed by exhaustively trying all possible solutions and choosing the best one. Because this is impractical in real-life industrial problems, automatic approaches are based on optimization meta-heuristics that search for sub-optimal but good enough solutions. These optimization techniques rely on the construction and evaluation of several solutions, thus requiring heavy geometric manipulation of the irregular polygons that constitute the problem data. Efficient processing of this geometric information is thus necessary to make effective fully automatic approaches to nesting problems in industrial environments. This paper describes Fafner, an FPGA-based custom computing machine that is used to accelerate the geometric operations, that are in the core of heuristic solutions to the nesting problem. The system is used as an auxiliary processor attached to a low cost personal computer, and combines a custom programmable processor with an array of custom circuits for the processing of irregular polygons.

Abstract
A new time-scale expansion algorithm based on a frequency-scale modification approach combined with tame interpolation is presented. The algorithm is noniterative and is constrained to a blind modification of the magnitudes and phases of the relevant spectral components of the signal, on a frame-by-frame basis. The resulting advantages and limitations are discussed. A few simplified models for signal analysis/synthesis are developed, the most critical of which concern phase and frequency estimation beyond the frequency resolution of the filterbank, The structure of the algorithm is described and its performance is illustrated with both synthetic and natural audio signals.

Abstract
A new technique for designing filters with long time constants in the discrete time domain is presented. The F&H (filter and hold) methodology halts the state of a continuous time filter every T seconds resulting in a filter implementation with time constants that can be controlled in three distinct ways: by the sampling period T, the duty cycle k = t/T or the time constant of the continuous time filter prototype. The final filter can be constructed from a typical Gm-C technique with very low power consumption.

Abstract
We investigate the coherence characteristics of multimode incoherent spatial solitons in noninstantaneous Kerr-like nonlinear media. Other properties of these incoherent solitons are also discussed as a function of their modal composition. [S1063-651X(99)04001-5].