An addendum on "Robust control of robots by the computed torque method"

We reinterprete and improve recent results on robust control of robots by the computed method. The methods and ideas used are inspired by `passivity based¿ control methods for robot manipulators and lead to a significant increase in freedom of controller implementation, thereby providing more flexibility to the designer of robot control systems

An approximate confidence interval for the difference between quantiles in a bio-medical problem

In this note it is described how two distributions arising in a bio-medical investigation are compared by means of a confidence interval for the difference of appropriate quantiles. It is briefly indicated how an approximation for such a confidence interval is derived

Linear modeling of possible mechanisms for parkinson tremor generation

The power of Parkinson tremor is expressed in terms of possibly changed frequency response functions between relevant variables in the neuromuscular system. The derivation starts out from a linear loopless equivalent model of mechanisms for general tremor generation. Hypothetical changes in this model from the substrate of the disease are indicated, and possible ones are inferred from literature about experiments on patients. The result indicates that in these patients tremor appears to have been generated in loops, which did not include the brain area which in surgery usually is inactivated. For some patients in the literature, these loops could involve muscle length receptors, the static sensitivity of which may have been enlarged by pathological brain activity

Relative linear power contribution with estimation statistics

The relative contribution by a noiselessly observed input signal to the power of a possibly disturbed observed stationary output signal from a linear system is expressed into signal spectral densities. Approximations of estimator statistics and derived confidence limits agree fairly well with simulation results for white signals

Improved approximation of bias in squared coherence estimates for weakly smooth spectra

Bias in squared coherence estimates for normal processes is approximated by a function of coherence and second derivatives divided by values of spectral densities which may vary slightly over the window width. The result approximates more accurately than a known formula results from nonrefuted literature concerning very smooth spectra

Magnus Hirschfeld, his biographies, and the possibilities and boundaries of ‘biography’ as ‘doing history

This article considers the two major biographies of sexologist Magnus Hirschfeld, MD (1868–1935), an early campaigner for ‘gay rights’ avant la lettre. Like him, his first biographerCharlotte Wolff (1897–1986) was a Jewish doctor who lived and worked in Weimar Republic Berlin and fled Germany when the Nazi regime came to power. When researching Hirschfeld’s biography (published in English in 1986) Wolff met a librarian and gay activist, Manfred Herzer, who would eventually be a cofounder of the Gay Museum in Berlin and publish (in German, in 1992) the other major Hirschfeld biography currently available. Using, inter alia, the correspondence between Wolff and Herzer, the article aims to explore and interrogate the boundaries and possibilities of ‘biography’ as a form of ‘doing history’