The Williams Conjecture is false for irreducible subshifts

We show the Williams Conjecture is false for irreducible shifts of finite type by examining relative sign-gyration numbers of conjugacies between shifts with no points of period one or two.Comment: 14 pages, published versio

Designing for Security: A Cybersecurity Introduction for Aerospace Education

Presented at the ICAS 33rd Congress 2022 as part of the 2021 AIAA Zarem Graduate Student Award for Distinguished Achievement in Aeronautics.The world is becoming increasingly digital-- the integration of communications, sensors, and data collection is becoming more and more prevalent in the Aerospace sector. Furthermore, the Aerospace sector plays a large role in connecting the world through air transportation networks, navigation satellites, information services, weather/environmental monitoring, and much more. Preventing disruptions to said networks is of utmost concern, with stability being a key factor in their construction. Recently, there has been a shift in computer science to push for security at a fundamental design level rather than a late-stage development consideration. In contrast, the Aerospace industry is only just now seeing a push to translate existing standards and implementing various cybersecurity practices. Even more troubling, many students’ first exposure to aerospace concepts in their undergraduate studies neglects to mention cybersecurity as a consideration. This paper serves as a cursory introduction of topics with the purpose of exposing the next generation of aerospace engineers to key areas where cybersecurity concepts will prove essential. Additionally, recommendations for integration into the educational curricula and the workplace are provided

Database Legislation: Changing Technologies Require Revised Laws

Symposium: The Constitutionality of Protecting Factual Compilation

Scattering matrices and expansion coefficients of Martian analogue palagonite particles

We present measurements of ratios of elements of the scattering matrix of Martian analogue palagonite particles for scattering angles ranging from 3 to 174 degrees and a wavelength of 632.8 nm. To facilitate the use of these measurements in radiative transfer calculations we have devised a method that enables us to obtain, from these measurements, a normalized synthetic scattering matrix covering the complete scattering angle range from 0 to 180 degrees. Our method is based on employing the coefficients of the expansions of scattering matrix elements into generalized spherical functions. The synthetic scattering matrix elements and/or the expansion coefficients obtained in this way, can be used to include multiple scattering by these irregularly shaped particles in (polarized) radiative transfer calculations, such as calculations of sunlight that is scattered in the dusty Martian atmosphere.Comment: 34 pages 7 figures 1 tabl

Segregated Early Weaning (SEW) of Pasture-farrowed Pigs

Segregated early weaning (SEW) works well with pasture-farrowed pigs. The SEW pasture-farrowed pigs weighed about the same as conventionally weaned pigs at 9 weeks of age with lower death losses (about 2% less). For the period 5–9 weeks of age the SEW pigs gained more rapidly and were more efficient converting feed to live gain than pigs weaned at 5 weeks of age and moved to an open-front shelter. However, costs were presumably higher for the SEW pigs because of higher labor costs from multiple feedings per day, higher-priced pig feed for early weaned pigs, higher utility costs, and the added cost of a nursery unit. Based on the results of this trial, SEW is compatible with pasture farrowing. However, pasture farrowing may not be as compatible with the mechanics of SEW. For example, because pasture farrowing is seasonal, the SEW nursery may not be kept full at all times. This would reduce the throughput, the number of pigs through the unit, which would increase the fixed building costs per pig. A new approach of putting newly weaned 2-week-old, 10-lb pigs directly into a finishing unit would partially alleviate this situation or lower fixed cost SEW nurseries are needed that then could be used on a seasonal basis. On the other hand, the technique of early weaning pasture-farrowed pigs has the potential of extending the farrowing season while reducing piglet mortality and minimizing the negative effects of weather extremes. By its nature, a one-litter pasture-farrowing system may benefit less from SEW than other more intensive or continuous pig production systems. In a one-litter system considerable age segregation of pigs occurs on the farm at all times. The sows are sold after weaning. At most times throughout the year the pigs on the farm are the same age. If the herd already has a high health status, the advantages of SEW are much less. Therefore, SEW will work for pasture farrowed pigs but herd health status and overall SEW costs need to be carefully evaluated. A cost comparison of SEW for pasture-farrowed pigs is elsewhere in this report

Extending and Redefining the Useful Life of Smatphones

Consumer culture and new technologies drive people to upgrade smartphones long before obsolescence is an issue. This creates a surplus of pocket-sized computers with vivid displays, a host of sensors and no clear-cut purpose in the world. The objective of this project is to radically influence how people understand their smartphones by reconstructing the context through which they are perceived

Active Adaptive Management in Insect Pest and Weed Control: Intervention with a Plan for Learning

A major problem in insect pest and weed management is uncertainty. Managers are faced with three main types of uncertainty: uncertainty about biological and environmental processes, and observational uncertainty. Active adaptive management (AAM) is management with a deliberate plan for learning about the managed system, so that management can be improved in the face of uncertainty. We discuss the potential benefits of applying AAM to insect pest and weed control with reference to a number of examples. We first address the possible uses for AAM in biological control, with particular reference to agent selection and release. We also propose applying AAM methods to resistance management and to spatial strategies for pest control. We conclude with an overview of AAM, a discussion of some of the potential limitations to its use in pest management, and the possibilities for increased implementation of AAM in the future