Penis size: Survey of female perceptions of sexual satisfaction

BACKGROUND: Does the size of the male penis, in terms of length or width, make a difference in female sexual satisfaction? METHOD: To study the effect of penis width vs. length on female sexual satisfaction, 50 sexually active female undergraduate students were asked which felt better, i. e., was penis width or length more important for their sexual satisfaction. RESULTS: None reported they did not know, or that width and length were equally satisfying. A large majority, 45 of 50, reported width was more important (p < .001). CONCLUSION: Implications are discussed, including the fact that the data seem to contradict Masters and Johnson about penis size having no physiological effect on female sexual satisfaction

Exponential Barycenters of the Canonical Cartan Connection and Invariant Means on Lie Groups

International audienceWhen performing statistics on elements of sets that possess a particular geometric structure, it is desirable to respect this structure. For instance in a Lie group, it would be judicious to have a notion of a mean which is stable by the group operations (composition and inversion). Such a property is ensured for Riemannian center of mass in Lie groups endowed with a bi-invariant Riemannian metric, like compact Lie groups (e.g. rotations). However, bi-invariant Riemannian metrics do not exist for most non compact and non-commutative Lie groups. This is the case in particular for rigid-body transformations in any dimension greater than one, which form the most simple Lie group involved in biomedical image registration. In this paper, we propose to replace the Riemannian metric by an affine connection structure on the group. We show that the canonical Cartan connections of a connected Lie group provides group geodesics which are completely consistent with the composition and inversion. With such a non-metric structure, the mean cannot be defined by minimizing the variance as in Riemannian Manifolds. However, the characterization of the mean as an exponential barycenter gives us an implicit definition of the mean using a general barycentric equation. Thanks to the properties of the canonical Cartan connection, this mean is naturally bi-invariant. We show the local existence and uniqueness of the invariant mean when the dispersion of the data is small enough. We also propose an iterative fixed point algorithm and demonstrate that the convergence to the invariant mean is at least linear. In the case of rigid-body transformations, we give a simple criterion for the global existence and uniqueness of the bi-invariant mean, which happens to be the same as for rotations. We also give closed forms for the bi-invariant mean in a number of simple but instructive cases, including 2D rigid transformations. For general linear transformations, we show that the bi-invariant mean is a generalization of the (scalar) geometric mean, since the determinant of the bi-invariant mean is the geometric mean of the determinants of the data. Finally, we extend the theory to higher order moments, in particular with the covariance which can be used to define a local bi-invariant Mahalanobis distance

Machines Finding Injustice

With rising caseloads, review systems are increasingly taxed, stymieing traditional methods of case screening. We propose an automated solution: predictive models of legal decisions can be used to identify and focus review resources on outlier decisions—those decisions that are most likely the product of biases, ideological extremism, unusual moods, and carelessness and thus most at odds with a court’s considered, collective judgment. By using algorithms to find and focus human attention on likely injustices, adjudication systems can largely sidestep the most serious objections to the use of algorithms in the law: that algorithms can embed racial biases, deprive parties of due process, impair transparency, and lead to “technological–legal lock-in.

Electrical, cryogenic and systems design of a dc superconducting power transmission line

The electrical, cryogenic, and systems design concepts for a dc superconducting power transmission line are discussed. The line consists of a hollow-core flexible coaxial cable, using multifilamentary or tape Nb/sub 3/Sn superconductor and wrapped tape dielectric, within a rigid cryogenic envelope. Cryogen flows through the core, is expanded in a turbine and returns over the outer cable surface. The concept is applied to power levels of 1 to 10 GW and for a range of line voltages and maximum dielectric stresses. Systems considerations define capacity ratings and optimum operating voltages. Cost estimates for the various components and cost optimizations are presented