Abstract: A signal separating device includes an iterative estimator, a repeating calculator, a result output unit, and a repetition controller. The repeating calculator repeatedly causes the iterative estimator to iteratively perform independent component analysis on an observed signal matrix, and to further perform independent component analysis on the source signal matrix obtained as a result. The result output unit outputs the product of the respective mixing matrices obtained during each repetition as a mixing matrix with respect to the observed signal matrix, while also outputting the source signal matrix obtained during the final repetition as a source signal matrix with respect to the observed signal matrix. The repetition controller causes the repeating calculator to repeat the calculation control until all mixing matrices and all source signal matrices satisfy a convergence condition. The iterative estimator may perform a fixed number of iterations, or perform iterations until convergence is obtained.

Abstract: A signal separating device includes an iterative estimator, a repeating calculator, a result output unit, and a repetition controller. The repeating calculator repeatedly causes the iterative estimator to iteratively perform independent component analysis on an observed signal matrix, and to further perform independent component analysis on the source signal matrix obtained as a result. The result output unit outputs the product of the respective mixing matrices obtained during each repetition as a mixing matrix with respect to the observed signal matrix, while also outputting the source signal matrix obtained during the final repetition as a source signal matrix with respect to the observed signal matrix. The repetition controller causes the repeating calculator to repeat the calculation control until all mixing matrices and all source signal matrices satisfy a convergence condition. The iterative estimator may perform a fixed number of iterations, or perform iterations until convergence is obtained.

Abstract: In a multimedia information providing system, responding to a preview request from a terminal equipment, a server device generates a chaotic random number sequence from an initial value allocated to the terminal equipment, mixes this sequence into a set of multimedia information as a noise signal at a first mixing ratio, and then transmits the result as a first set of multimedia information for distribution. Responding to a quality improvement request, the server device generates a chaotic number sequence from the initial value allocated to the terminal equipment, mixes this sequence into a set of multimedia information as a noise signal at a second mixing ratio, and then transmits the result as a second set of multimedia information for distribution. The terminal equipment performs component analysis on the first and second sets of multimedia information, removing the noise and restoring a high-quality version.