1,104 research outputs found
Low-Velocity Halo Clouds
Models that reproduce the observed high-velocity clouds (HVCs) also predict
clouds at lower radial velocities that may easily be confused with Galactic
disk (|z| < 1 kpc) gas. We describe the first search for these low-velocity
halo clouds (LVHCs) using IRAS data and the initial data from the Galactic
Arecibo L-band Feed Array survey in HI (GALFA-HI). The technique is based upon
the expectation that such clouds should, like HVCs, have very limited infrared
thermal dust emission as compared to their HI column density. We describe our
'displacement-map' technique for robustly determining the dust-to-gas ratio of
clouds and the associated errors that takes into account the significant
scatter in the infrared flux from the Galactic disk gas. We find that there
exist lower-velocity clouds that have extremely low dust-to-gas ratios,
consistent with being in the Galactic halo - candidate LVHCs. We also confirm
the lack of dust in many HVCs with the notable exception of complex M, which we
consider to be the first detection of warm dust in HVCs. We do not confirm the
previously reported detection of dust in complex C. In addition, we find that
most Intermediate- and Low-Velocity clouds that are part of the Galactic disk
have a higher 60 micron/100 micron flux ratio than is typically seen in
Galactic HI, which is consistent with a previously proposed picture in which
fast-moving Galactic clouds have smaller, hotter dust grains.Comment: 30 pages, 7 figures. Accepted to the Ap
Support for graphicacy: a review of textbooks available to accounting students
This Teaching Note reports on the support available in textbooks for graphicacy that will help students understand the complexities of graphical displays. Graphical displays play a significant role in financial reporting, and studies have found evidence of measurement distortion and selection bias. To understand the complexities of graphical displays, students need a sound understanding of graphicacy and support from the textbooks available to them to develop that understanding. The Teaching Note reports on a survey that examined the textbooks available to students attending two Scottish universities. The support of critical graphicacy skills was examined in conjunction with textbook characteristics. The survey, which was not restricted to textbooks designated as required reading, examined the textbooks for content on data measurement and graphical displays. The findings highlight a lack of support for graphicacy in the textbooks selected. The study concludes that accounting educators need to scrutinize more closely the selection of textbooks and calls for more extensive research into textbooks as a pedagogic tool
Advancing Critical Care in the ICU: A Human-Centered Biomedical Data Visualization Systems
The purpose of this research is to provide medical clinicians with a new technology for interpreting large and diverse datasets to expedite critical care decision-making in the ICU. We refer to this technology as the medical information visualization assistant (MIVA). MIVA delivers multivariate biometric (bedside) data via a visualization display by transforming and organizing it into temporal resolutions that can provide contextual knowledge to clinicians. The result is a spatial organization of multiple datasets that allows rapid analysis and interpretation of trends. Findings from the usability study of the MIVA static prototype and heuristic inspection of the dynamic prototype suggest that using MIVA can yield faster and more accurate results. Furthermore, comments from the majority of the experimental group and the heuristic inspectors indicate that MIVA can facilitate clinical task flow in context-dependent health care settings
Quantifying the Performance of Individual Players in a Team Activity
Teamwork is a fundamental aspect of many human activities, from business to art and from sports to science. Recent research suggest that team work is of crucial importance to cutting-edge scientific research, but little is known about how teamwork leads to greater creativity. Indeed, for many team activities, it is not even clear how to assign credit to individual team members. Remarkably, at least in the context of sports, there is usually a broad consensus on who are the top performers and on what qualifies as an outstanding performance.In order to determine how individual features can be quantified, and as a test bed for other team-based human activities, we analyze the performance of players in the European Cup 2008 soccer tournament. We develop a network approach that provides a powerful quantification of the contributions of individual players and of overall team performance.We hypothesize that generalizations of our approach could be useful in other contexts where quantification of the contributions of individual team members is important
Geocoronal H-A [Alpha] Intensity Measurements Using the Wisconsin H-A [Alpha] Mapper Fabry-Perot Facility
The Wisconsin H-a [alpha] Mapper (WHAM), a remotely operable, semi-automated Fabry-Perot located at Kitt Peak Observatory, has been making an all-sky survey of interstellar hydrogen Balmer a [alpha] (H-a [alpha]) emissions since 1997. Using the annular summing spectroscopy technique, WHAM has acquired ~[approx.] 37,000 spectra to date, spanning almost 100 nights of observations. Since all of the galactic emission spectral data contain the terrestrial H-a [alpha] (6562.7 Ă
) emission line, these measurements constitute a rich source of geocoronal data for investigating natural variability in the upper atmosphere. The WHAM observations also serve as a benchmark for comparison with future data. Analysis of the first year of WHAM data shows only small day-to-day variations after shadow altitude variations are taken into account. For example, at shadow altitudes of 2000 and 3000 km, the RMS scatter is within approximately +/- 20%; this variability is expected to be reduced with accurate accounting of the smaller-scale effects of observational slant path, zenith angle, and azimuth on the H-a [alpha] intensity. This result is consistent with past midlatitude Wisconsin data sets but different from observations made by other observers and instruments at the low-latitude Arecibo site. The multiple viewing geometries of the observations provide stringent modeling constraints, useful in testing current modeling capabilities. Modeling of the WHAM data with a global nonisothermal resonance radiation transport code (lyao_rt) indicates that the signal-to-noise of the data is sufficient to determine relative variations in upper atmospheric atomic hydrogen column densities to better than 5%. This paper describes the WHAM aeronomy program and its observational scheme, analysis procedures, and results from data taken in 1997. Case study comparisons are made with past data sets and with predictions from the lyao_rt resonant radiation transport modeling code of Bishop [1999]
Impression management and retrospective sense-making in corporate annual reports: banks' graphical reporting during the global financial crisis
This study investigates two potentially complementary reporting scenarios in annual reports: reactive impression management and retrospective sense-making. It examines stock market performance graphs in European listed banks? annual reports before and during the global financial crisis. Our results indicate that banks reacted to the global financial crisis by omitting stock market performance graphs from the annual report and from its most prominent sections. On the other hand, banks reduced favorable distortions and favorable performance comparisons. No significant evidence of retrospective sense-making is found. Overall, the findings are consistent with impression management incorporating human cognitive biases, with companies preferring misrepresentation by omission over misrepresentation by commission. Under high public scrutiny, banks appear to seek to provide a more favorable view by concealing negative information rather than by favorable distortions or comparisons. The study contributes to the development of impression management theories. It uses a psychological interpretation that incorporates human cognitive biases, rather than adopting a purely economically based perspective
GiViP: A Visual Profiler for Distributed Graph Processing Systems
Analyzing large-scale graphs provides valuable insights in different
application scenarios. While many graph processing systems working on top of
distributed infrastructures have been proposed to deal with big graphs, the
tasks of profiling and debugging their massive computations remain time
consuming and error-prone. This paper presents GiViP, a visual profiler for
distributed graph processing systems based on a Pregel-like computation model.
GiViP captures the huge amount of messages exchanged throughout a computation
and provides an interactive user interface for the visual analysis of the
collected data. We show how to take advantage of GiViP to detect anomalies
related to the computation and to the infrastructure, such as slow computing
units and anomalous message patterns.Comment: Appears in the Proceedings of the 25th International Symposium on
Graph Drawing and Network Visualization (GD 2017
The role of usability engineering in the development of an intelligent decision support system
This paper presents an overview of the usability engineering process for the development of a personalised clinical decision support system for the management of type 1 diabetes. The tool uses artificial intelligence (AI) techniques to provide insulin bolus dose advice and carbohydrate recommendations that adapt to the individual. We describe the role of human factors and user-centred design in the creation of medical systems that must adhere to international standards. We focus specifically on the formative evaluation stage of this process. The preliminary analysis of data shows promising results
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