A History of Travel in America

"The work is tonic for Americans, especially in these times, when we take for granted the four-day ocean steamship and the 90-hour transcontinental train.

A Graph-Theoretical Approach to the Harmonic Analysis of Georgian Vocal Polyphonic Music

The present paper proposes a computational approach to the comparative analysis and visualization of the harmonic structure of three-voiced vocal music. The dataset which has been used in this study is the same as in Scherbaum et al. (2015), a corpus of polyphonic songs from Svaneti (Akhobadze, 1957). Similar to the earlier work, a song is treated as a discrete temporal process in which harmonic or melodic states change according to unknown rules which are implicitely contained in the song itself. In contrast to the prior study, however, there are no assumptions regarding their probabilistic or deterministic nature

Opportunistic detection of atrial fibrillation using blood pressure monitors: a systematic review

Background: Atrial Fibrillation (AF) affects around 2% of the population and early detection is beneficial, allowing patients to begin potentially life-saving anticoagulant therapies. Blood pressure (BP) monitors may offer an opportunity to screen for AF. Aim: To identify and appraise studies which report the diagnostic accuracy of automated BP monitors used for opportunistic AF detection. Methods: A systematic search was performed of the Medline, Medline-in-process and Embase literature databases. Papers were eligible if they described primary studies of the evaluation of a BP device for AF detection, were published in a peer reviewed journal and reported values for the sensitivity and specificity. Included studies were appraised using the QUADAS-2 tool to assess their risk of bias and applicability to opportunistic AF detection. Values for the sensitivity and specificity of AF detection were extracted from each paper and compared. Results and Conclusion: We identified seven papers evaluating six devices from two manufacturers. Only one study scored low risk in all of the QUADAS-2 domains. All studies reported specificity greater than 85% and six reported sensitivity greater than 90%. The studies showed that blood pressure devices with embedded algorithms for detecting arrhythmias show promise as screening tools for AF, comparing favourably with manual pulse palpation. But the studies used different methodologies and many were subject to potential bias. More studies are needed to more precisely define the sensitivity and specificity of opportunistic screening for AF during blood pressure measurement before its clinical utility in the population of interest can be assessed fully

Accuracy of pulse interval timing in ambulatory blood pressure measurement

Blood pressure (BP) monitors rely on pulse detection. Some blood pressure monitors use pulse timings to analyse pulse interval variability for arrhythmia screening, but this assumes that the pulse interval timings detected from BP cuffs are accurate compared with RR intervals derived from ECG. In this study we compared the accuracy of pulse intervals detected using an ambulatory blood pressure monitor (ABPM) with single lead ECG. Twenty participants wore an ABPM for three hours and a data logger which synchronously measured cuff pressure and ECG. RR intervals were compared with corresponding intervals derived from the cuff pressure tracings using three different pulse landmarks. Linear mixed effects models were used to assess differences between ECG and cuff pressure timings and to investigate the effect of potential covariates. In addition, the maximum number of successive oscillometric beats detectable in a measurement was assessed. From 243 BP measurements, the foot landmark of the oscillometric pulse was found to be associated with fewest covariates and had a random error of 9.5 ms. 99% of the cuff pressure recordings had more than 10 successive detectable oscillometric beats. RR intervals can be accurately estimated using an ABPM

An Intelligent Early Warning System for Software Quality Improvement and Project Management

One of the main reasons behind unfruitful software development projects is that it is often too late to correct the problems by the time they are detected. It clearly indicates the need for early warning about the potential risks. In this paper, we discuss an intelligent software early warning system based on fuzzy logic using an integrated set of software metrics. It helps to assess risks associated with being behind schedule, over budget, and poor quality in software development and maintenance from multiple perspectives. It handles incomplete, inaccurate, and imprecise information, and resolve conflicts in an uncertain environment in its software risk assessment using fuzzy linguistic variables, fuzzy sets, and fuzzy inference rules. Process, product, and organizational metrics are collected or computed based on solid software models. The intelligent risk assessment process consists of the following steps: fuzzification of software metrics, rule firing, derivation and aggregation of resulted risk fuzzy sets, and defuzzification of linguistic risk variables

Quantum Hall States of High Symmetry

We identify some hidden symmetries of Chern-Simons theories, such as appear in the effective theory for quantized Hall states. This allows us to determine which filling fractions admit spin-singlet quantum Hall states. Our results shed some light on states already observed at $\nu=2/3$, and transitions between them. We identify SU(2), or higher, symmetries of many additional states -- including spin-polarized states. Our symmetries classify low-lying excited states and may be of use in the construction of trial wavefunctions, but are typically not present in the edge theory, where they are lifted by non-universal couplings.Comment: 17 pages, PostScript, 1 figure included. Revision - corrected slight error in equation (3.5) on Page