A configurable decoder for pin-limited applications

Pin limitation is the restriction imposed on an IC chip by the unavailability of a sufficient number of I/O pins. This impacts the design and performance of the chip, as the amount of information that can be passed through the boundary of the chip becomes limited. One area that would benefit from a reduction of the effect of pin limitation is reconfigurable architectures. In this work, we consider reconfigurable devices called Field Programmable Gate Arrays (FPGAs). Due to pin limitation, current FPGAs use a form of 1-hot decoder to select elements (one frame at a time) during partial reconfiguration. This results in a slow and coarse selection of elements for reconfiguration. We propose a module that performs a focused selection of only those elements that require reconfiguration. This reduces reconfiguration overheads and enables the speeds needed for dynamic reconfiguration. The problem is that of selecting subsets of an n-element set in a fast, focused and inexpensive manner. This thesis proposes such a configurable decoder that bridges the gap between the inexpensive, but inflexible, fixed 1-hot decoder, and the expensive, but flexible, pure LUT-based decoder. Our configurable decoder uses a LUT with a narrow output and a low cost in tandem with a special fixed decoder called a mapping unit that expands the output of the LUT to a desired n-bit output. We demonstrate several implementations of the mapping unit, each with different capabilities and trade-offs. A key result of this work is that for any gate cost G=O(n logk n) (where k is a constant), if a pure LUT-based solution produces λ independent subsets, then our method produces Ω(λ log n / log log n) independent subsets for the same cost. Our decoder also produces many more dependent subsets (that depend on the choice of the Ω( λ log n / log log n) independent subsets). We provide simulation results for the configurable decoder and predict future trends from the simulation data; these confirm the theoretical advantages of the proposed decoder. We illustrate the implementation of important subset classes on our configurable decoder and make key observations on a generalized variant

A Dense Reference Network for Mass-Market Centimeter-Accurate Positioning

The quality of atmospheric corrections provided by a dense reference network for centimeter-accurate carrierphase differential GNSS (CDGNSS) positioning is investigated. A dense reference network (less than 20 km inter-station distance) offers significant benefits for mass-market users, enabling lowcost (including single-frequency) CDGNSS positioning with rapid integer ambiguity resolution. Precise positioning on a massmarket platform would significantly influence the world economy, ushering in a host of consumer-focused applications such as globally-registered augmented and virtual reality and improved all-weather safety and efficiency for intelligent transportation systems, applications which have so far been hampered by the several-meter-level errors in standard GNSS positioning. This contribution examines CDGNSS integer ambiguity resolution performance in terms of network correction uncertainty, and network correction uncertainty, in turn, in terms of network density. It considers the total error in network corrections: a sum of ionospheric, tropospheric, and reference station multipath components. The paper’s primary goal is to identify the network density beyond which mass-market users would see no further significant improvement in ambiguity resolution performance. It finishes by describing development and deployment of a low-cost dense reference network in Austin, Texas.Aerospace Engineering and Engineering Mechanic

Characterizing the Cutaneous Microbiome of the Peaks of Otter Salamander (Plethodon hubrichti) in the Context of Infectious Disease

Undergraduate Basi

Blueprint for a high-performance biomaterial: full-length spider dragline silk genes.

Spider dragline (major ampullate) silk outperforms virtually all other natural and manmade materials in terms of tensile strength and toughness. For this reason, the mass-production of artificial spider silks through transgenic technologies has been a major goal of biomimetics research. Although all known arthropod silk proteins are extremely large (>200 kiloDaltons), recombinant spider silks have been designed from short and incomplete cDNAs, the only available sequences. Here we describe the first full-length spider silk gene sequences and their flanking regions. These genes encode the MaSp1 and MaSp2 proteins that compose the black widow's high-performance dragline silk. Each gene includes a single enormous exon (>9000 base pairs) that translates into a highly repetitive polypeptide. Patterns of variation among sequence repeats at the amino acid and nucleotide levels indicate that the interaction of selection, intergenic recombination, and intragenic recombination governs the evolution of these highly unusual, modular proteins. Phylogenetic footprinting revealed putative regulatory elements in non-coding flanking sequences. Conservation of both upstream and downstream flanking sequences was especially striking between the two paralogous black widow major ampullate silk genes. Because these genes are co-expressed within the same silk gland, there may have been selection for similarity in regulatory regions. Our new data provide complete templates for synthesis of recombinant silk proteins that significantly improve the degree to which artificial silks mimic natural spider dragline fibers

Complexity among the finitely generated subgroups of Thompson's group

Funding: Acknowledgements. The authors would also like to thank the referee for their very careful and thorough reading of the paper. This publication is in part a product of a visit of the first and third author to the Mathematisches Forschungsinstitut Oberwolfach, Germany in December 2016 as part of their Research In Pairs program. The third author was partially supported by NSF grants DMS–1600635 and DMS-1854367.We demonstrate the existence of a family of finitely generated subgroups of Richard Thompson’s group F which is strictly well-ordered by the embeddability relation of type ε0 + 1. All except the maximum element of this family (which is F itself) are elementary amenable groups. In fact we also obtain, for each α < ε0, a finitely generated elementary amenable subgroup of F whose EA-class is α + 2. These groups all have simple, explicit descriptions and can be viewed as a natural continuation of the progression which starts with Z + Z, Z wr Z, and the Brin-Navas group B. We also give an example of a pair of finitely generated elementary amenable subgroups of F with the property that neither is embeddable into the other.PostprintPeer reviewe

Patient Engagement in Cosmetic Designing of Prostheses: Current Practice and Potential Outcome Benefits

Purpose: Making a prosthesis for an individual with limb loss is a highly personalized process. A currently unexplored area is whether there are tangible benefits in greater patient engagement during the making of their prostheses. We examined the current practice of engaging patients in prosthetic cosmetic designing and identified factors associated with patient outcomes. Methods: This cross-sectional study surveyed 104 prosthetists and 25 prostheses users. The questionnaires covered aspects of prosthetic prescription, users’ perceived level of engagement, and self-reported outcomes. Regression analyses were used to examine the associations between perceived level of engagement, satisfaction, and other outcomes. Results: Among prosthesis users, 75% reported being offered at least one cosmetic option during the making of their prostheses which corresponded with 82.7% of the prosthetists reporting that they typically engage patients in their practices. Patients who were offered at least one cosmetic design option reported significantly greater satisfaction than those that were not offered the option (p=0.027). Patients’ level of satisfaction was significantly correlated with a perception that their prostheses empower them in daily activities (r=0.415, p=0.028). Conclusion: Engaging patients in the cosmetic designing of their prosthesis is a widely accepted practice. Prosthetic practitioners should consider the potential benefits of higher levels engagement for all patients. Clinical Relevance: Limb loss is a complex health condition that impacts patient’s physical and psychological functioning and wellbeing. Engaging patients in the prosthetic design process is a ubiquitous practice, however some prosthetists may offer higher levels of cosmetic options only to certain populations. Higher levels of engagement in the prostheses-making process support patients’ senses of autonomy and empowerment and is related to greater prosthetic compliance

Mid-Infrared Studies of Galactic sources: Probing the Relationship Between Polycyclic Aromatic Hydrocarbons and their Physical Environment

Over the past 50 years, prominent mid-infrared (MIR) emission features from 3--20 $\mu$m have been observed ubiquitously in the interstellar medium (ISM) of Galactic and extragalactic sources. These emission features arise from the vibrational relaxation of polycyclic aromatic hydrocarbons (PAHs) after the absorption of a far-ultraviolet (FUV) photon. PAHs are astronomically significant in that they contain up to 15\% of the cosmic carbon inventory and play an important role in the physical and chemical processes of the ISM such as, for example, the gas heating and the ionization balance. Variations in the relative strengths of the major PAH bands can be used to understand their underlying molecular properties and their interaction with the surrounding photodissociation regions (PDR) environment. We employ these variations to characterize the PAH populations in terms of properties such as degree of ionization and sizes and investigate their dependence on the physical conditions such as the FUV radiation field strength, the gas density and the gas temperature for nearby spatially resolved Galactic PDRs. We find both size and charge tend to rise with increasing radiation field strength or proximity to the illuminating source. Correlations between PAH emission features in spatially resolved sources are found to be highly dependent on the PDR morphology (i.e. edge-on versus face-on) and environmental conditions. These results are indicative of significant UV processing driving the photochemical evolution of astronomical PAH populations. We utilize observations of far-infrared (FIR) cooling lines of atoms and the FIR dust continuum emission of a nearby reflection nebula in combination with PDR models to derive maps of the physical conditions. Comparing these derived physical conditions with PAH emission characteristics at a matching spatial resolution and apertures allows us to critically test previous established relationships between PAH emission and these physical conditions. From these results, we show that these relationships also hold at a higher spatial resolution than previously obtained

Progress around the Boone-Higman Conjecture

A conjecture of Boone and Higman from the 1970's asserts that a finitely generated group $G$ has solvable word problem if and only if $G$ can be embedded into a finitely presented simple group. We comment on the history of this conjecture and survey recent results that establish the conjecture for many large classes of interesting groups.Comment: 21 page