John S. Perkins

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An approach to derive relationships for defining land degradation and desertification risk and developing appropriate tools for assessing the effectiveness of the various land management practices using indicators is presented in the present paper. In order to investigate which indicators are most effective in assessing the level of desertification risk, a(More)
Indicator-based approaches are often used to monitor land degradation and desertification from the global to the very local scale. However, there is still little agreement on which indicators may best reflect both status and trends of these phenomena. In this study, various processes of land degradation and desertification have been analyzed in 17 study(More)
This paper identifies new ways of moving from land degradation towards sustainable land management through the development of economic mechanisms. It identifies new mechanisms to tackle land degradation based on retaining critical levels of natural capital whilst basing livelihoods on a wider range of ecosystem services. This is achieved through a case(More)
Applications to ocean acoustic data from a towed array and to speech processing are presented for an improved optimal time-domain beamformer, which involves optimizing over all possible source bearings and time series for multiple sources using simulated annealing. The convergence of the parameter search is accelerated by accepting time series perturbations(More)
This report documents the theory and numerical implementation of a method to invert underwater acoustic measurements for geo-acoustic parameters. The inversion is accomplished by searching for the parameter values that produce the best match between simulated data and observed data. An error function, usually called the cost function, is de ned to measure(More)
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