11,765 research outputs found
The ASCCR Frame for Learning Essential Collaboration Skills
Statistics and data science are especially collaborative disciplines that
typically require practitioners to interact with many different people or
groups. Consequently, interdisciplinary collaboration skills are part of the
personal and professional skills essential for success as an applied
statistician or data scientist. These skills are learnable and teachable, and
learning and improving collaboration skills provides a way to enhance one's
practice of statistics and data science. To help individuals learn these skills
and organizations to teach them, we have developed a framework covering five
essential components of statistical collaboration: Attitude, Structure,
Content, Communication, and Relationship. We call this the ASCCR Frame. This
framework can be incorporated into formal training programs in the classroom or
on the job and can also be used by individuals through self-study. We show how
this framework can be applied specifically to statisticians and data scientists
to improve their collaboration skills and their interdisciplinary impact. We
believe that the ASCCR Frame can help organize and stimulate research and
teaching in interdisciplinary collaboration and call on individuals and
organizations to begin generating evidence regarding its effectiveness.Comment: 12 pages, 1 figure. Updated to this Version 5 by adding a few more
references, discussing how to teach ASCCR in the classroom, calling on others
to add to research supporting the use of the ASCCR Frame, and adding
discussion of ethics and reproducible researc
Investigating the role of the land surface in explaining the interannual variation of the net radiation balance over the Western Sahara and sub-Sahara
The status of the data sets is discussed. Progress was made in both data analysis and modeling areas. The atmospheric and land surface contributions to the net radiation budget over the Sahara-Sahel region is being decoupled. The interannual variability of these two processes was investigated and this variability related to seasonal rainfall fluctuations. A modified Barnes objective analysis scheme was developed which uses an eliptic scan pattern and a 3-pass iteration of the difference fields
Biplot and Singular Value Decomposition Macros for Excel©
The biplot display is a graph of row and column markers obtained from data that forms a two-way table. The markers are calculated from the singular value decomposition of the data matrix. The biplot display may be used with many multivariate methods to display relationships between variables and objects. It is commonly used in ecological applications to plot relationships between species and sites. This paper describes a set of Excelé macros that may be used to draw a biplot display based on results from principal components analysis, correspondence analysis, canonical discriminant analysis, metric multidimensional scaling, redundancy analysis, canonical correlation analysis or canonical correspondence analysis. The macros allow for a variety of transformations of the data prior to the singular value decomposition and scaling of the markers following the decomposition.
What the 2008 Stock Market Crash Means for Retirement Security
Compares future retirement resources before and after the stock market decline, by gender, marital status, race/ethnicity, education, and retirement income quintile, under three scenarios: no recovery, full recovery, and partial recovery in ten years
GreenCare for Children -- Measuring Environmental Hazards in the Childcare Industry
Presents findings from a two-year survey administered to a random sampling of childcare providers. Developed and interpreted by a diverse team of industry, technical, and educational experts
Diffusion of Lexical Change in Social Media
Computer-mediated communication is driving fundamental changes in the nature
of written language. We investigate these changes by statistical analysis of a
dataset comprising 107 million Twitter messages (authored by 2.7 million unique
user accounts). Using a latent vector autoregressive model to aggregate across
thousands of words, we identify high-level patterns in diffusion of linguistic
change over the United States. Our model is robust to unpredictable changes in
Twitter's sampling rate, and provides a probabilistic characterization of the
relationship of macro-scale linguistic influence to a set of demographic and
geographic predictors. The results of this analysis offer support for prior
arguments that focus on geographical proximity and population size. However,
demographic similarity -- especially with regard to race -- plays an even more
central role, as cities with similar racial demographics are far more likely to
share linguistic influence. Rather than moving towards a single unified
"netspeak" dialect, language evolution in computer-mediated communication
reproduces existing fault lines in spoken American English.Comment: preprint of PLOS-ONE paper from November 2014; PLoS ONE 9(11) e11311
Topological Chaos in a Three-Dimensional Spherical Fluid Vortex
In chaotic deterministic systems, seemingly stochastic behavior is generated
by relatively simple, though hidden, organizing rules and structures. Prominent
among the tools used to characterize this complexity in 1D and 2D systems are
techniques which exploit the topology of dynamically invariant structures.
However, the path to extending many such topological techniques to three
dimensions is filled with roadblocks that prevent their application to a wider
variety of physical systems. Here, we overcome these roadblocks and
successfully analyze a realistic model of 3D fluid advection, by extending the
homotopic lobe dynamics (HLD) technique, previously developed for 2D
area-preserving dynamics, to 3D volume-preserving dynamics. We start with
numerically-generated finite-time chaotic-scattering data for particles
entrained in a spherical fluid vortex, and use this data to build a symbolic
representation of the dynamics. We then use this symbolic representation to
explain and predict the self-similar fractal structure of the scattering data,
to compute bounds on the topological entropy, a fundamental measure of mixing,
and to discover two different mixing mechanisms, which stretch 2D material
surfaces and 1D material curves in distinct ways.Comment: 14 pages, 11 figure
A comparison of surface sensible and latent heat fluxes from aircraft and surface measurements in FIFE 1987
Surface fluxes of sensible and latent heat over a tall-grass prairie in central Kansas, as measured by 22 surface stations during FIFE 1987, are compared with values gained indirectly by linear extrapolation of aircraft-measured flux profiles to the surface. The results of 33 such comparisons covering the period 26 June to 13 October 1987 indicate that the sensible heat flux profiles were generally more linear with less scatter in the measurements at each level than were the latent heat flux profiles, the profile extrapolations of sensible heat flux in general underestimate the surface averages by about 30 percent, with slightly better agreement during periods of small flux, and the profile extrapolations of latent heat flux in general underestimate the surface averages by about 15 percent, with overestimates during periods of small fluxes (dry conditions) and overestimates during periods of large fluxes (moist conditions). Possible origins of the differences between the two sets of measurements are discussed, as directions for further research
Strawman Philosophical Guide for Developing International Network of GPM GV Sites
The creation of an international network of ground validation (GV) sites that will support the Global Precipitation Measurement (GPM) Mission's international science programme will require detailed planning of mechanisms for exchanging technical information, GV data products, and scientific results. An important component of the planning will be the philosophical guide under which the network will grow and emerge as a successful element of the GPM Mission. This philosophical guide should be able to serve the mission in developing scientific pathways for ground validation research which will ensure the highest possible quality measurement record of global precipitation products. The philosophical issues, in this regard, partly stem from the financial architecture under which the GV network will be developed, i.e., each participating country will provide its own financial support through committed institutions -- regardless of whether a national or international space agency is involved.At the 1st International GPM Ground Validation Workshop held in Abingdon, UK in November-2003, most of the basic tenants behind the development of the international GV network were identified and discussed. Therefore, with this progress in mind, this presentation is intended to put forth a strawman philosophical guide supporting the development of the international network of GPM GV sites, noting that the initial progress has been reported in the Proceedings of the 1st International GPM GV Workshop -- available online. The central philosophical issues themselves, all flow from the fact that each participating institution can only bring to the table, GV facilities and scientific personnel that are affordable to the sanctioning (funding) national agency (be that a research, research-support, or operational agency). This situation imposes on the network, heterogeneity in the measuring sensors, data collection periods, data collection procedures, data latencies, and data reporting capabilities. Therefore, in order for the network to be effective in supporting the central scientific goals of the GPM mission, there must be a basic agreed upon doctrine under which the network participants function vis-a-vis: (1) an overriding set of general scientific requirements, (2) a minimal set of policies governing the free flow of GV data between the scientific participants, (3) a few basic definitions concerning the prioritization of measurements and their respective value to the mission, (4) a few basic procedures concerning data formats, data reporting procedures, data access, and data archiving, and (5) a simple means to differentiate GV sites according to their level of effort and ability to perform near real-time data acquisition - data reporting tasks. Most important, in case they choose to operate as a near real-time data collection-data distribution site, they would be expected to operate under a fairly narrowly defined protocol needed to ensure smooth GV support operations. This presentation will suggest measures responsive to items (1) - (5) from which to proceed,. In addition, this presentation will seek to stimulate discussion and debate concerning how much heterogeneity is tolerable within the eventual GV site network, given that the any individual GV site can only be considered scientifically useful if it supports the achievement of the central GPM Mission goals. Only ground validation research that has a direct connection to the space mission should be considered justifiable given the overarching scientific goals of the mission. Therefore each site will have to seek some level of accommodation to what the GPM Mission requires in the way of retrieval error characterization, retrieval error detection and reporting, and generation of GV data products that support assessment and improvement of the mission's standard precipitation retrieval algorithms. These are all important scientific issues that will be best resolved in open scientific debate
Differentiating the role of land surface variability and cloudiness variability on global energy transport within the atmosphere and oceans
The following provides the final report on NASA IDP Project NAGW-1840 'Differentiating the Role of Land Surface Variability on Global Energy Transport within the Atmosphere and Oceans'. The project was designed to investigate the role of regional perturbations in the earth radiation budget on atmospheric and oceanic energy transports on an interannual basis. We proposed a modeling strategy based on an entropy extremum principle that could be used to separate the transports into oceanic and atmospheric components so as to better understand the effects of regional perturbations at the distinct atmospheric and oceanic time scales. The original focus was to consider the maintenance and year-to-year modulation of a large-scale, low-latitude North African-West Pacific Ocean net radiation dipole, which we had detected in the Nimbus 6 and 7 record of earth radiation budget measurements, and which necessitated significant cross-meridional energy transports to maintain global equilibrium. In addition, perturbations in the radiation balance term were to be partitioned into cloud-induced and surface-induced components to better understand the feedbacks between clouds and surface boundary conditions on interannual variability of the radiation balance
- …