Stochastic Analysis of Synchronization in a Supermarket Refrigeration System

Display cases in supermarket systems often exhibit synchronization, in which the expansion valves in the display cases turn on and off at exactly the same time. The study of the influence of switching noise on synchronization in supermarket refrigeration systems is the subject matter of this work. For this purpose, we model it as a hybrid system, for which synchronization corresponds to a periodic trajectory. Subsequently, we investigate the influence of switching noise. We develop a statistical method for computing an intensity function, which measures how often the refrigeration system stays synchronized. By analyzing the intensity, we conclude that the increase in measurement uncertainty yields the decrease at the prevalence of synchronization.Comment: In Proceedings HAS 2014, arXiv:1501.0540

Generic features of modulational instability in nonlocal Kerr media

The modulational instability (MI) of plane waves in nonlocal Kerr media is studied for a general, localized, response function. It is shown that there always exists a finite number of well-separated MI gain bands, with each of them characterised by a unique maximal growth rate. This is a general property and is demonstrated here for the Gaussian, exponential, and rectangular response functions. In case of a focusing nonlinearity it is shown that although the nonlocality tends to suppress MI, it can never remove it completely, irrespectively of the particular shape of the response function. For a defocusing nonlinearity the stability properties depend sensitively on the profile of the response function. It is shown that plane waves are always stable for response functions with a positive-definite spectrum, such as Gaussians and exponentials. On the other hand, response functions whose spectra change sign (e.g., rectangular) will lead to MI in the high wavenumber regime, provided the typical length scale of the response function exceeds a certain threshold. Finally, we address the case of generalized multi-component response functions consisting of a weighted sum of N response functions with known properties.Comment: 9 pages, 5 figure

Letter from Richmond, CA Shipyard Number Two Special Investigator John Rasmussen regarding Richard Auras\u27s Character, 1945

An August 12, 1945 letter from John Rasmussen, special investigator for the Richmond, CA Shipyard Number Two, addressed To Whom It May Concern, in support of Richard Auras. Rasmussen says he knows Auras, who is now interned as an alien enemy in Bismarck, ND, as a loyal alien of the United States. He says Auras has not shown signs of negative opinions of the U.S. or its form of government and, given the opportunity, would make a loyal American citizen. See also: Petition and Affidavit By Curt Benedict arguing for overturn of denial of release of Richard Auras from Internment, 1946 Letter from Richard Auras to William Langer regarding his internment status decision, 1946https://commons.und.edu/langer-papers/1160/thumbnail.jp