Distributional Properties of the Largest Prime Factor

http://www.math.missouri.edu/~bbanks/papers/index.htmlLet P(n) denote the largest prime factor of an integer n ≥ 2, and put P(1) = 1. In this paper, we study the distribution of the sequence {P(n) : n ≥ 1} over the set of congruence classes modulo an integer q ≥ 2, and we study the same question for the sequence {P(p − 1) : p is prime}. We also give bounds for rational exponential sums involving P(n). Finally, for an irrational number _, we show that the sequence {_P(n) : n ≥ 1} is uniformly distributed modulo 1

Improved Thermoelectric Cooling Based on the Thomson Effect

Traditional thermoelectric Peltier coolers exhibit a cooling limit which is primarily determined by the figure of merit, zT. Rather than a fundamental thermodynamic limit, this bound can be traced to the difficulty of maintaining thermoelectric compatibility. Self-compatibility locally maximizes the cooler's coefficient of performance for a given zT and can be achieved by adjusting the relative ratio of the thermoelectric transport properties that make up zT. In this study, we investigate the theoretical performance of thermoelectric coolers that maintain self-compatibility across the device. We find such a device behaves very differently from a Peltier cooler, and term self-compatible coolers "Thomson coolers" when the Fourier heat divergence is dominated by the Thomson, as opposed to the Joule, term. A Thomson cooler requires an exponentially rising Seebeck coefficient with increasing temperature, while traditional Peltier coolers, such as those used commercially, have comparatively minimal change in Seebeck coefficient with temperature. When reasonable material property bounds are placed on the thermoelectric leg, the Thomson cooler is predicted to achieve approximately twice the maximum temperature drop of a traditional Peltier cooler with equivalent figure of merit (zT). We anticipate the development of Thomson coolers will ultimately lead to solid state cooling to cryogenic temperatures.Comment: The Manuscript has been revised for publication in PR

Research and experimental study for the development of a 1000 watt CW space environment S-band power amplifier

One thousand watt continuous wave space environment S band power amplifier developmen

Development of an Objective Structured Clinical Examination as a Component of Assessment for Initial Board Certification in Anesthesiology.

With its first administration of an Objective Structured Clinical Examination (OSCE) in 2018, the American Board of Anesthesiology (ABA) became the first US medical specialty certifying board to incorporate this type of assessment into its high-stakes certification examination system. The fundamental rationale for the ABA's introduction of the OSCE is to include an assessment that allows candidates for board certification to demonstrate what they actually "do" in domains relevant to clinical practice. Inherent in this rationale is that the OSCE will capture competencies not well assessed in the current written and oral examinations-competencies that will allow the ABA to judge whether a candidate meets the standards expected for board certification more properly. This special article describes the ABA's journey from initial conceptualization through first administration of the OSCE, including the format of the OSCE, the process for scenario development, the standardized patient program that supports OSCE administration, examiner training, scoring, and future assessment of reliability, validity, and impact of the OSCE. This information will be beneficial to both those involved in the initial certification process, such as residency graduate candidates and program directors, and others contemplating the use of high-stakes summative OSCE assessments

Evaluating implicit feedback models using searcher simulations

In this article we describe an evaluation of relevance feedback (RF) algorithms using searcher simulations. Since these algorithms select additional terms for query modification based on inferences made from searcher interaction, not on relevance information searchers explicitly provide (as in traditional RF), we refer to them as implicit feedback models. We introduce six different models that base their decisions on the interactions of searchers and use different approaches to rank query modification terms. The aim of this article is to determine which of these models should be used to assist searchers in the systems we develop. To evaluate these models we used searcher simulations that afforded us more control over the experimental conditions than experiments with human subjects and allowed complex interaction to be modeled without the need for costly human experimentation. The simulation-based evaluation methodology measures how well the models learn the distribution of terms across relevant documents (i.e., learn what information is relevant) and how well they improve search effectiveness (i.e., create effective search queries). Our findings show that an implicit feedback model based on Jeffrey's rule of conditioning outperformed other models under investigation

Novel colours and the content of experience

I propose a counterexample to naturalistic representational theories of phenomenal character. The counterexample is generated by experiences of novel colours reported by Crane and Piantanida. I consider various replies that a representationalist might make, including whether novel colours could be possible colours of objects and whether one can account for novel colours as one would account for binary colours or colour mixtures. I argue that none of these strategies is successful and therefore that one cannot fully explain the nature of the phenomenal character of perceptual experiences using a naturalistic conception of representation

Probabilistic models of information retrieval based on measuring the divergence from randomness

We introduce and create a framework for deriving probabilistic models of Information Retrieval. The models are nonparametric models of IR obtained in the language model approach. We derive term-weighting models by measuring the divergence of the actual term distribution from that obtained under a random process. Among the random processes we study the binomial distribution and Bose--Einstein statistics. We define two types of term frequency normalization for tuning term weights in the document--query matching process. The first normalization assumes that documents have the same length and measures the information gain with the observed term once it has been accepted as a good descriptor of the observed document. The second normalization is related to the document length and to other statistics. These two normalization methods are applied to the basic models in succession to obtain weighting formulae. Results show that our framework produces different nonparametric models forming baseline alternatives to the standard tf-idf model

Close encounters of a critical kind: a diffractive musing in/between new material feminism and object-oriented ontology

For a number of years, new material feminists have been developing new theoretical tools, new modes of conceptual analysis and new ethical frameworks. Object-oriented ontology, part of the speculative realism ‘movement’, has been engaged in something similar. Yet these endeavours have often taken place in ‘parallel universes’, despite sharing – or at least colliding around – a range of somewhat similar ontological and epistemological commitments. Composed as a diffractive musing encounter in which insights are read ‘through one another’ (Barad, 2007: 25) in order to ‘attend to … details and specificities of relations of difference and how they matter’ (Barad, 2007:71), the article brings Barad’s Meeting the Universe Halfway, already a ‘foundational’ text for new material feminism, into an encounter with a speculative realist text of the same ‘foundational’ status, Harman’s The Quadruple Object. The article develops a notion of diffractive musing as embodied, sensory struggle which instantiates intellectual generosity as a mode of critique. Following this, it puts diffractive musing to work theoretically via an encounter between object-oriented ontology and new material feminism. Keywords : new material feminism, speculative realism, diffraction, musing, critiqu

Learning To Be Affected: Social suffering and total pain at life’s borders.

The practice of Live Sociology in situations of pain and suffering is the author’s focus. An outline of the challenges of understanding pain is followed by a discussion of Bourdieu’s ‘social suffering’ (1999) and the palliative care philosophy of ‘total pain’. Using examples from qualitative research on disadvantaged dying migrants in the UK, attention is given to the methods that are improvised by dying people and care practitioners in attempts to bridge intersubjective divides, where the causes and routes of pain can be ontologically and temporally indeterminate and/or withdrawn. The paper contends that these latter phenomena are the incitement for the inventive bridging and performative work of care and Live Sociological methods, both of which are concerned with opposing suffering. Drawing from the ontology of total pain, I highlight the importance of (i) an engagement with a range of materials out of which attempts at intersubjective bridging can be produced, and which exceed the social, the material, and the temporally linear; and (ii) an empirical sensibility that is hospitable to the inaccessible and non-relational