956 research outputs found
Testing the Role of Technical Information in Public Risk Perception
It is widely believed that more detail about health effects and likely exposure routes is apt to reduce citizens\u27 concerns about low-probability Risks. The authors\u27 study suggests that providing such detail may not be as useful as, e.g., addressing public concerns and keeping citizens current on officials\u27 actions
Defining user perception of distributed multimedia quality
This article presents the results of a study that explored the human side of the multimedia experience. We propose a model that assesses quality variation from three distinct levels: the network, the media and the content levels; and from two views: the technical and the user perspective. By facilitating parameter variation at each of the quality levels and from each of the perspectives, we were able to examine their impact on user quality perception. Results show that a significant reduction in frame rate does not proportionally reduce the user's understanding of the presentation independent of technical parameters, that multimedia content type significantly impacts user information assimilation, user level of enjoyment, and user perception of quality, and that the device display type impacts user information assimilation and user perception of quality. Finally, to ensure the transfer of information, low-level abstraction (network-level) parameters, such as delay and jitter, should be adapted; to maintain the user's level of enjoyment, high-level abstraction quality parameters (content-level), such as the appropriate use of display screens, should be adapted
Public Perceptions of Regulatory Costs, Their Uncertainty and Interindividual Distribution
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/122430/1/risa12532.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/122430/2/risa12532_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/122430/3/risa12532-sup-0001-SupMat.pd
Some Fundamental Properties of a Multivariate von Mises Distribution
In application areas like bioinformatics multivariate distributions on angles
are encountered which show significant clustering. One approach to statistical
modelling of such situations is to use mixtures of unimodal distributions. In
the literature (Mardia et al., 2011), the multivariate von Mises distribution,
also known as the multivariate sine distribution, has been suggested for
components of such models, but work in the area has been hampered by the fact
that no good criteria for the von Mises distribution to be unimodal were
available. In this article we study the question about when a multivariate von
Mises distribution is unimodal. We give sufficient criteria for this to be the
case and show examples of distributions with multiple modes when these criteria
are violated. In addition, we propose a method to generate samples from the von
Mises distribution in the case of high concentration.Comment: fixed a typo in the article title, minor fixes throughou
Teaching TEI: The Need for TEI by Example
The Text Encoding Initiative (TEI)1 has provided a complex and comprehensive system of provisions for scholarly text encoding. Although a major focus of the ‘digital humanities’ domain, and despite much teaching effort by the TEI community, there is a lack of teaching materials available, which would encourage the adoption of the TEI's recommendations and the widespread use of its text encoding guidelines in the wider academic community. This article describes the background, plans, and aims of the TEI by Example project, and why we believe it is a necessary addition to the materials currently provided by the TEI itself. The teaching materials currently available are not suited to the needs of self directed learners, and the development of stand alone, online tutorials in the TEI are an essential addition to the extant resources, in order to encourage and facilitate the uptake of TEI by both individuals and institutions
AN ANALYSIS ON THE EFFECTS OF ADDITIVE MANUFACTURING (AM) ON F/A-18E/F READINESS
This research paper focuses on the Boeing F/A-18E and the F/A-18F Super Hornet aviation depot level repairable (AVDLR) parts process and the potential effects of additive manufacturing (AM) on that process. The motivation for study was spurred by recent reports indicating that the F/A-18E/F is experiencing decreased operational readiness due to increases in maintenance-related impacts related to parts availability, long lead times, and increased parts failure frequency. This study aimed to determine the requirements for interjecting AM into the Intermediate level repair process in order to make a significant impact on F/A-18E/F depot-level repairable part lead times. More specifically, this research analyzes the potential impact of various AM production levels on overall lead times. Facilitation of this research project was accomplished through mathematical modeling and by conducting simulations based on various assumptions and probability distributions. Eight simulations were conducted, each with different AM production time assumptions. Resultant outputs reflected 19 different scenarios simulating 0%–90% production of AM at the Intermediate Maintenance level. Results indicate that AM has the potential to decrease overall expected lead time averages if AM production can be kept to less than approximately 30 days.Lieutenant, United States NavyLieutenant, United States NavyLieutenant Commander, United States NavyApproved for public release. Distribution is unlimited
Mean-field methods in evolutionary duplication-innovation-loss models for the genome-level repertoire of protein domains
We present a combined mean-field and simulation approach to different models
describing the dynamics of classes formed by elements that can appear,
disappear or copy themselves. These models, related to a paradigm
duplication-innovation model known as Chinese Restaurant Process, are devised
to reproduce the scaling behavior observed in the genome-wide repertoire of
protein domains of all known species. In view of these data, we discuss the
qualitative and quantitative differences of the alternative model formulations,
focusing in particular on the roles of element loss and of the specificity of
empirical domain classes.Comment: 10 Figures, 2 Table
Hierarchical Chain Model of Spider Capture Silk Elasticity
Spider capture silk is a biomaterial with both high strength and high
elasticity, but the structural design principle underlying these remarkable
properties is still unknown. It was revealed recently by atomic force
microscopy that, an exponential force--extension relationship holds both for
capture silk mesostructures and for intact capture silk fibers [N. Becker et
al., Nature Materials 2, 278 (2003)]. In this Letter a simple hierarchical
chain model was proposed to understand and reproduce this striking observation.
In the hierarchical chain model, a polymer is composed of many structural
motifs which organize into structural modules and supra-modules in a
hierarchical manner. Each module in this hierarchy has its own characteristic
force. The repetitive patterns in the amino acid sequence of the major
flagelliform protein of spider capture silk is in support of this model.Comment: 4 pages, 3 figures. Will be formally published in PR
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