Distance learning is rapidly becoming pervasive in every aspect of education. From elementary school through doctoral programs, information technology enables self-paced learning with some degree of distance from teaching professionals. Educators sometimes begin this online delivery system without fully examining the academic soundness of this approach. Other considerations are administrative m...

We investigate the properties of the host galaxies of X–ray selected (high frequency peaked) BL Lac objects using a large and homogeneous data set of high spatial resolution R–band observations of 52 BL Lacs in the EMSS and Slew samples. The redshift distribution of the BL Lacs ranges from z = 0.04 to z>0.7, with average and median redshifts z = 0.26 and z = 0.24, respectively. Eight objects ar...

Cosmological numerical simulations of galaxy formation have led to the cuspy density profile of pure cold dark matter halo toward the center, which is in sharp contradiction with the observations of the rotation curves of cold dark matter-dominated dwarf and low surface brightness disk galaxies, the latter tends to favor mass profiles with a flat central core. Many efforts have been devoted to ...

We define pure intuitionistic differential proof nets, extending Ehrhard and Regnier’s differential interaction nets with the exponential box of Linear Logic. Normalization of the exponential reduction and confluence of the full one is proved. These results are directed and adjusted to give a translation of Boudol’s untyped λ-calculus with resources extended with a linear-non linear reduction à...

A central problem in time series analysis is prediction of a future observation. The theory of optimal linear prediction has been well understood since the seminal work of A. Kolmogorov and N. Wiener during World War II. A simplifying assumption is to assume that one-step-ahead prediction is carried out based on observing the infinite past of the time series. In practice, however, only a finite...