Non-standard binary representations and the Stern sequence

We show that the number of short binary signed-digit representations of an integer $n$ is equal to the $n$-th term in the Stern sequence. Various proofs are provided, including direct, bijective, and generating function proofs. We also show that this result can be derived from recent work of Monroe on binary signed-digit representations of a fixed length

Whole body interaction in abstract domains

Whole Body Interaction appears to be a good fit of interaction style for some categories of application domain, such as the motion capture of gestures for computer games and virtual physical sports. However, the suitability of whole body interaction for more abstract application domains is less apparent, and the creation of appropriate whole body interaction designs for complex abstract areas such as mathematics, programming and musical harmony remains challenging. We argue, illustrated by a detailed case study, that conceptual metaphor theory and sensory motor contingency theory offer analytic and synthetic tools whereby whole body interaction can in principle be applied usefully to arbitrary abstract application domains. We present the case study of a whole body interaction system for a highly abstract application area, tonal harmony in music. We demonstrate ways in which whole body interaction offers strong affordances for action and insight in this domain when appropriate conceptual metaphors are harnessed in the design. We outline how this approach can be applied to abstract domains in general, and discuss its limitations.Published versio

Representations of integers as quotients of sums of distinct powers of three

Which integers can be written as a quotient of sums of distinct powers of three? We outline our first steps toward an answer to this question, beginning with a necessary and almost sufficient condition. Then we discuss an algorithm that indicates whether it is possible to represent a given integer as a quotient of sums of distinct powers of three. When the given integer is representable, this same algorithm generates all possible representations. We develop a categorization of representations based on their connections to $0,1$-polynomials and give a complete description of the types of representations for all integers up to 364. Finally, we discuss in detail the representations of 7, 22, 34, 64, and 100, as well as some infinite families of integers

An evaluation of low-level automation navigation functions upon vessel traffic services work practices

The Sea Traffic Management (STM) Validation Project is a European-based initiative with ambitions to improve maritime safety and efficiency through information sharing in real time. The purpose of this paper is to evaluate the “STM services,” which can be categorized as low-level automated functions designed to improve information exchange between ship and shore. Full-scale simulated scenarios were developed and tested on 16 professional vessel traffic service (VTS) operators comparing VTS operations as they are today with the added STM functionality. Data collection involved observations which assessed the frequency and type of interactions between ships and VTS, followed by questionnaires to provide an overall assessment of the user experience. The results indicate that the frequency and method of communication patterns between VTS operators and ships will be affected by the integration of the STM services. Additional access to navigational information could change the role of VTS operators in traffic situations compared with traditional operations. This paper discusses the findings from a socio-technical systems perspective while also addressing the individual STM services and their potential impact on VTS operations. This research provides valuable information for European VTS centers that could be affected by the implementation of e-Navigation and, specifically, the STM services

Graphs admitting only constant splines

We study {\em generalized graph splines,} introduced by Gilbert, Viel, and the last author. For a large class of rings, we characterize the graphs that only admit constant splines. To do this, we prove that if a graph has a particular type of cutset (e.g., a bridge), then the space of splines naturally decomposes as a certain direct sum of submodules. As an application, we use these results to describe splines on a triangulation studied by Zhou and Lai, but over a different ring than they used.Comment: 19 pages; this version has substantial revisions, and is the version accepted by the Pacific Journal of Mathematic

Graphs Admitting Only Constant Splines

We study generalized graph splines, introduced by Gilbert, Tymoczko, and Viel (2016). For a large class of rings, we characterize the graphs that only admit constant splines. To do this, we prove that if a graph has a particular type of cutset (e.g., a bridge), then the space of splines naturally decomposes as a certain direct sum of submodules. As an application, we use these results to describe splines on a triangulation studied by Zhou and Lai, but over a different ring than they used

Short-Term Thermal Acclimation Modifies the Metabolic Condition of the Coral Holobiont

The nutritional symbiosis between coral hosts and photosynthetic dinoflagellates is fundamental to the functioning of coral reefs. Rising seawater temperatures destabilize this relationship, resulting in drastic declines in world-wide coral cover. Thermal history is thought to play an important role in shaping a coral\u27s response to subsequent thermal stress. Here, we exposed Pocillopora damicornis to two thermal acclimation regimes (ambient vs. warm) and compared the effect that acclimation had on the coral holobiont\u27s response to a subsequent seven day heat stress event. We conducted daily physiological measurements at the holobiont level (gross photosynthesis, respiration, host protein content, symbiont density and chlorophyll content) throughout the heating event, as well as cellular-level imaging of 13C-bicarbonate and 15N-nitrate assimilation (using NanoSIMS) at the end of the heat stress event. Thermal acclimation history had a negligible effect on the measurements conducted at the holobiont level during the heat stress event. No differences were observed in the O2-budget between ambient and warm-acclimated corals and only small fluctuations in host protein, symbiont density and chlorophyll content were detected. In contrast, this lack of differential response, was not mirrored at the cellular level. Warm-acclimated corals had substantially higher 13C enrichment in the host gastrodermis and lipid bodies, but significantly lower 15N-nitrate assimilation in the symbionts and the host tissue layers, relative to the ambient-acclimated corals. We discuss potential reasons for the disconnect that occurred between symbiont bicarbonate and nitrate assimilation (in the absence of photosynthetic breakdown) in the warm-acclimated corals. We suggest this represents either a shift in nitrogen utilization, or supply limitation by the host. Our findings raise several interesting hypotheses regarding the role that nitrogen metabolism plays in thermal stress, which will warrant further investigation if we are to understand the acclimatization capacity of the coral holobiont

Preterm birth, unplanned hospital contact, and mortality in infants born to teenage mothers in five countries: An administrative data cohort study.

BACKGROUND: Young maternal age is associated with lower birthweight and higher rates of preterm birth and childhood hospitalisations. Internationally, teen pregnancy rates vary widely, reflecting differences in social, welfare, and health care factors in different cultural contexts. OBJECTIVES: To determine whether the increased risk of adverse infant outcomes among teenage mothers varies by country, reflecting different national teenage birth rates and country-specific social/welfare policies, in Scotland (higher teenage pregnancy rates), England, New South Wales (NSW; Australia), Ontario (Canada), and Sweden (lower rates). METHODS: We used administrative hospital data capturing 3 002 749 singleton births surviving to postnatal discharge between 2010 and 2014 (2008-2012 for Sweden). We compared preterm birth (24-36 weeks' gestation), mortality within 12 months of postnatal discharge, unplanned hospital admissions, and emergency department visits within 12 months of postnatal discharge, for infants born to mothers aged 15-19, 20-24, 25-29, and 30-34 years. RESULTS: Compared to births to women aged 30-34 years, risks of adverse outcomes among teenage mothers were higher in all countries, but the magnitude of effects was not related to country-specific rates of teenage births. Teenage mothers had between 1.2% (95% confidence interval [CI] 0.7, 1.7, Sweden) and 2.0% (95% CI 1.4, 2.5, NSW) more preterm births, and between 9.8 (95% CI 7.2, 12.4, England) and 19.7 (95% CI 8.7, 30.6, Scotland) more deaths per 10 000 infants, compared with mothers aged 30-34. Between 6.4% (95% CI 5.5, 7.4, NSW) and 25.4% (95% CI 24.7, 26.1, Ontario), more infants born to teenage mothers had unplanned hospital contacts compared with those born to mothers aged 30-34. CONCLUSIONS: Regardless of country, infants born to teenage mothers had universally worse outcomes than those born to older mothers. This excess risk did not vary by national rates of livebirths to teenage mothers. Current mechanisms to support teenage mothers have not eliminated maternal age-related disparities in infant outcomes; further strategies to mitigate excess risk in all countries are needed

Senior Recital: Thomas Kieffer, alto saxophone and Tyler Elvidge, trumpet

This recital is presented in partial fulfillment of requirements for the degrees Bachelor of Music in Music Education. Mr. Kieffer studies saxophone with Sam Skelton. Mr. Elvidge studies trumpet with Douglas Lindsey.https://digitalcommons.kennesaw.edu/musicprograms/1179/thumbnail.jp