Polynomial-time Solvable #CSP Problems via Algebraic Models and Pfaffian Circuits

A Pfaffian circuit is a tensor contraction network where the edges are labeled with changes of bases in such a way that a very specific set of combinatorial properties are satisfied. By modeling the permissible changes of bases as systems of polynomial equations, and then solving via computation, we are able to identify classes of 0/1 planar #CSP problems solvable in polynomial-time via the Pfaffian circuit evaluation theorem (a variant of L. Valiant's Holant Theorem). We present two different models of 0/1 variables, one that is possible under a homogeneous change of basis, and one that is possible under a heterogeneous change of basis only. We enumerate a series of 1,2,3, and 4-arity gates/cogates that represent constraints, and define a class of constraints that is possible under the assumption of a ``bridge" between two particular changes of bases. We discuss the issue of planarity of Pfaffian circuits, and demonstrate possible directions in algebraic computation for designing a Pfaffian tensor contraction network fragment that can simulate a swap gate/cogate. We conclude by developing the notion of a decomposable gate/cogate, and discuss the computational benefits of this definition

Low-authority control synthesis for large space structures

The control of vibrations of large space structures by distributed sensors and actuators is studied. A procedure is developed for calculating the feedback loop gains required to achieve specified amounts of damping. For moderate damping (Low Authority Control) the procedure is purely algebraic, but it can be applied iteratively when larger amounts of damping are required and is generalized for arbitrary time invariant systems

Gyrodampers for large space structures

The problem of controlling the vibrations of a large space structures by the use of actively augmented damping devices distributed throughout the structure is addressed. The gyrodamper which consists of a set of single gimbal control moment gyros which are actively controlled to extract the structural vibratory energy through the local rotational deformations of the structure, is described and analyzed. Various linear and nonlinear dynamic simulations of gyrodamped beams are shown, including results on self-induced vibrations due to sensor noise and rotor imbalance. The complete nonlinear dynamic equations are included. The problem of designing and sizing a system of gyrodampers for a given structure, or extrapolating results for one gyrodamped structure to another is solved in terms of scaling laws. Novel scaling laws for gyro systems are derived, based upon fundamental physical principles, and various examples are given

Designed-in security for cyber-physical systems

An expert from academia, one from a cyber-physical system (CPS) provider, and one from an end asset owner and user offer their different perspectives on the meaning and challenges of 'designed-in security.' The academic highlights foundational issues and talks about emerging technology that can help us design and implement secure software in CPSs. The vendor's view includes components of the academic view but emphasizes the secure system development process and the standards that the system must satisfy. The user issues a call to action and offers ideas that will ensure progress

Furthering post-human political ecologies

This critical review aims to facilitate explicit, ongoing consideration for how post-human geographies and polit- ical ecology stand to bene t one another empirically and theoretically. In it, we argue that post-human political ecologies are well-equipped to ensure that the broader post-human turn in geographical thought engages criti- cally with the roles that humans and non-humans play in enactments of injustice – both as subjects of (in)justice and as beings whose actions have justice implications for myriad forms of life. By engaging with empirics drawn from research on tiger conservation in India, we deploy myth as a conceptual tool and as an heuristic device to illustrate how post-human political ecologies might further engage with the politics and power asymmetries em- bedded in conservation science and practice. To conclude, this critical review summarizes the merits of bringing the ‘cutting edge’ of post-human geographical literature into dialogue with the traditional concerns of political ecology and recaps the potential power that myth retains as an analytic in post-human political ecologies

Game-Theoretic, Interposable Communication

Recent advances in distributed epistemologies and ubiquitous configurations have paved the way for superpages. Here, we show the explo- ration of thin clients. Here we disprove not only that superpages can be made “fuzzy”, “fuzzy”, and knowledge-based, but that the same is true for the UNIVAC computer

Analysis of the Extent to Which State Insurance Laws Mandate Coverage and Payment of Vaccines and Vaccine Administration Fees during Periods of Declared Public Health Emergencies

This analysis examines whether state insurance laws require health insurers, as a condition of doing business, to pay the costs associated with the administration of immunizations during declared public health emergencies. As is the case with the current H1N1 emergency, a public health emergency triggers nationwide distribution of free vaccine. But even when vaccine is distributed free of charge, its administration poses costs to private physicians and charges can be significant. As a result, the Institute of Medicine has identified vaccine administration as a potential financial barrier to care. Most communities have limited numbers of public health workers and professional health care volunteers, making private sector involvement essential

Analysis of State Medicaid Agency Performance in Relation to Incentivizing the Provision of H1N1 Immunizations to Eligible Populations

This analysis examines the extent to which state Medicaid agencies have translated a recent CMS guidance on vaccine coverage into clear information for participating providers clarifying payment for costs associated with the administration of H1N1 vaccines. This clarification may be particularly important in states that do not otherwise cover and pay for recommended immunizations as part of treating adult patients