Voter Model Perturbations and Reaction Diffusion Equations

We consider particle systems that are perturbations of the voter model and show that when space and time are rescaled the system converges to a solution of a reaction diffusion equation in dimensions $d \ge 3$. Combining this result with properties of the PDE, some methods arising from a low density super-Brownian limit theorem, and a block construction, we give general, and often asymptotically sharp, conditions for the existence of non-trivial stationary distributions, and for extinction of one type. As applications, we describe the phase diagrams of three systems when the parameters are close to the voter model: (i) a stochastic spatial Lotka-Volterra model of Neuhauser and Pacala, (ii) a model of the evolution of cooperation of Ohtsuki, Hauert, Lieberman, and Nowak, and (iii) a continuous time version of the non-linear voter model of Molofsky, Durrett, Dushoff, Griffeath, and Levin. The first application confirms a conjecture of Cox and Perkins and the second confirms a conjecture of Ohtsuki et al in the context of certain infinite graphs. An important feature of our general results is that they do not require the process to be attractive.Comment: 106 pages, 7 figure

Development and Flight Results from the C3D2 Imager Payload on AlSat Nano

An experimental CubeSat camera system using 3 separate CMOS imagers was flown in 2014 on UKube-1. In response to an announcement opportunity in December 2014, we proposed an upgrade to our C3D imager payload, which was accepted to fly on AlSat Nano. Launched in September 2016 the system has been operational for over 1 year and has returned both images and housekeeping data, including detailed temperature and radiation dosimetry measurements. Through these in-orbit demonstrations on CubeSans, the image sensors and payload have attained TRL9, and these are now being used in other flight opportunities. In this paper we describe the C3D imager payload, which comprises 3 independent CMOS image sensors used in different camera systems; two wide field cameras are specifically optimised with one to observe the Earth from the 650 km orbit, and the other with its focus set to 40 cm to observe a deployable boom from the CubeSat. The experiment controller also contained thermometry and two RADFET dosimeters, one located on the payload, with the other deployed at a different point on the spacecraft. In this paper we will describe the experiment design and operational performance, and review the in-orbit data obtained during the operations covering over 17 months in-orbit, in addition to discussing lessons learned from the flight experience. We also discuss further developments of the payload concept which we are currently working on toward future flight opportunities

Observations of the Habits of \u3ci\u3eCorthylus Punctatissimus\u3c/i\u3e (Coleoptera: Scolytidae) Infesting Maple Saplings in Central Michigan

Corthylus punctatissimus, the pitted ambrosia beetle, infested and killed maple saplings that were 3-12 years of age with a basal diameter of 4-14 mm. The habits of the parental pair of adults are described. The beetles construct a spiral gallery system with about five egg niches per host. Half the brood reaches adult stage during the summer with a sex ratio of 1:1. No relationship was found between the number of niches, length of gallery system, or diameter of stem

Diffusion in a generalized Rubinstein-Duke model of electrophoresis with kinematic disorder

Using a generalized Rubinstein-Duke model we prove rigorously that kinematic disorder leaves the prediction of standard reptation theory for the scaling of the diffusion constant in the limit for long polymer chains $D \propto L^{-2}$ unaffected. Based on an analytical calculation as well as Monte Carlo simulations we predict kinematic disorder to affect the center of mass diffusion constant of an entangled polymer in the limit for long chains by the same factor as single particle diffusion in a random barrier model.Comment: 29 pages, 3 figures, submitted to PR

Air Monitoring for Hazardous Gas Detection

The Hazardous Gas Detection Lab (HGDL) at Kennedy Space Center is involved in the design and development of instrumentation that can detect and quantify various hazardous gases. Traditionally these systems are designed for leak detection of the cryogenic gases used for the propulsion of the Shuttle and other vehicles. Mass spectrometers are the basis of these systems, which provide excellent quantitation, sensitivity, selectivity, response times and detection limits. A Table lists common gases monitored for aerospace applications. The first five gases, hydrogen, helium, nitrogen, oxygen, and argon are historically the focus of the HGDL

Kobe and Curly

The author remembers Kobe Bryant and Fred Curly Neal

A Stormwater Overflow Control Device

On Lake Eola, stormwater runoff has been identified as a major source of pollution. Other lakes in Central Florida are experiencing similar decay due to stormwater runoff. A device has been examined for diversion of the initial flows to treatment before discharge into the lake. A graphical aid was developed to select the proper volume required for the device and was applied to a Lake Eola existing collection basin. A laboratory model was designed and constructed based on the scaled-down version of a collecting basin on Lake Eola. This model was used to demonstrate the concept, as well as, indicate the effects of several critical design variables. Recommendations on design for a Lake Eola device were made for possible improvements in the system itself

Planning for High Net-WOrth U.S. Persons Through the Use of Offshore Life Insurance

Sophisticated planning for the high net-worth United States citizens often includes the use of offshore variable life insurance. Such leading edge planning is accomplished through structures that provide income, gift, estate, and generation-skipping transfer tax planning not available domestically. In addition to providing sophisticated tax and estate planning benefits, variable life insurance policies issued by foreign-based carriers have numerous economic advantages

Regular Incidence Complexes, Polytopes, and C-Groups

Regular incidence complexes are combinatorial incidence structures generalizing regular convex polytopes, regular complex polytopes, various types of incidence geometries, and many other highly symmetric objects. The special case of abstract regular polytopes has been well-studied. The paper describes the combinatorial structure of a regular incidence complex in terms of a system of distinguished generating subgroups of its automorphism group or a flag-transitive subgroup. Then the groups admitting a flag-transitive action on an incidence complex are characterized as generalized string C-groups. Further, extensions of regular incidence complexes are studied, and certain incidence complexes particularly close to abstract polytopes, called abstract polytope complexes, are investigated.Comment: 24 pages; to appear in "Discrete Geometry and Symmetry", M. Conder, A. Deza, and A. Ivic Weiss (eds), Springe

Keeping Score One Score Later

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68404/2/10.1177_104687818902000204.pd