Home About us Contact
|
Home About us Contact | ||
|
|
||
Data Visualization (data + visualization)
Selected AbstractsLattice: Multivariate Data Visualization with R by Deepayan SarkarINTERNATIONAL STATISTICAL REVIEW, Issue 3 2008Klaus Nordhausen No abstract is available for this article. [source] The Role of Statistics in the Data Revolution?INTERNATIONAL STATISTICAL REVIEW, Issue 1 2001Jerome H. Friedman Summary The nature of data is rapidly changing. Data sets are becoming increasingly large and complex. Modern methodology for analyzing these new types of data are emerging from the fields of Data Base Managment, Artificial Intelligence, Machine Learning, Pattern Recognition, and Data Visualization. So far Statistics as a field has played a minor role. This paper explores some of the reasons for this, and why statisticians should have an interest in participating in the development of new methods for large and complex data sets. [source] ModEco: an integrated software package for ecological niche modelingECOGRAPHY, Issue 4 2010Qinghua Guo ModEco is a software package for ecological niche modeling. It integrates a range of niche modeling methods within a geographical information system. ModEco provides a user friendly platform that enables users to explore, analyze, and model species distribution data with relative ease. ModEco has several unique features: 1) it deals with different types of ecological observation data, such as presence and absence data, presence-only data, and abundance data; 2) it provides a range of models when dealing with presence-only data, such as presence-only models, pseudo-absence models, background vs presence data models, and ensemble models; and 3) it includes relatively comprehensive tools for data visualization, feature selection, and accuracy assessment. [source] Discovering hidden knowledge in data classification via multivariate analysisEXPERT SYSTEMS, Issue 2 2010Yisong Chen Abstract: A new classification algorithm based on multivariate analysis is proposed to discover and simulate the grading policy on school transcript data sets. The framework comprises three major steps. First, factor analysis is adopted to separate the scores of several different subjects into grading-related ones and grading-unrelated ones. Second, multidimensional scaling is employed for dimensionality reduction to facilitate subsequent data visualization and interpretation. Finally, a support vector machine is trained to classify the filtered data into different grades. This work provides an attractive framework for intelligent data analysis and decision making. It also exhibits the advantages of high classification accuracy and supports intuitive data interpretation. [source] GENOMIZER: an integrated analysis system for genome-wide association data,HUMAN MUTATION, Issue 6 2006Andre Franke Abstract Genome-wide association analysis appears to be a promising way to identify heritable susceptibility factors for complex human disorders. However, the feasibility of large-scale genotyping experiments is currently limited by an incomplete marker coverage of the genome, a restricted understanding of the functional role of given genomic regions, and the small sample sizes used. Thus, genome-wide association analysis will be a screening tool to facilitate subsequent gene discovery rather than a means to completely resolve individual genetic risk profiles. The validation of association findings will continue to rely upon the replication of "leads" in independent samples from either the same or different populations. Even under such pragmatic conditions, the timely analysis of the large data sets in question poses serious technical challenges. We have therefore developed public-domain software, GENOMIZER, that implements the workflow of an association experiment, including data management, single-point and haplotype analysis, "lead" definition, and data visualization. GENOMIZER (www.ikmb.uni-kiel.de/genomizer) comes with a complete user manual, and is open-source software licensed under the GNU Lesser General Public License. We suggest that the use of this software will facilitate the handling and interpretation of the currently emerging genome-wide association data. Hum Mutat 27(6), 583,588, 2006. © 2006 Wiley-Liss, Inc. [source] xBCI: A Generic Platform for Development of an Online BCI SystemIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 4 2010I Putu Susila Non-member Abstract A generic platform for realizing an online brain,computer interface (BCI) named xBCI was developed. The platform consists of several functional modules (components), such as data acquisition, storage, mathematical operations, signal processing, network communication, data visualization, experiment control, and real-time feedback presentation. Users can easily build their own BCI systems by combining the components on a graphical-user-interface (GUI) based diagram editor. They can also extend the platform by adding components as plug-ins or by creating components using a scripting language. The platform works on multiple operating systems and supports parallel (multi-threaded) data processing and data transfer to other PCs through a network transmission control protocol/internet protocol or user datagram protocol (TCP/IP or UDP). A BCI system based on motor imagery and a steady-state visual evoked potential (SSVEP) based BCI system were constructed and tested on the platform. The results show that the platform is able to process multichannel brain signals in real time. The platform provides users with an easy-to-use system development tool and reduces the time needed to develop a BCI system. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Orthogonality of silver-ion and non-aqueous reversed-phase HPLC/MS in the analysis of complex natural mixtures of triacylglycerolsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 21 2009Michal Hol Abstract The goal of this work is the study of possibilities of two basic separation modes used in the analysis of complex triacylglycerol (TG) samples of plant oils and animal fats, i.e. non-aqueous reversed-phase (NARP) and silver-ion HPLC coupled with atmospheric pressure chemical ionization mass spectrometry (APCI-MS). The orthogonality of both separation modes is tested for complex TG mixtures containing fatty acids (FAs) with different acyl chain lengths, different number, positions and geometry of double bonds (DBs) and different regioisomeric positions of FAs on the glycerol skeleton. The retention in NARP mode is governed by the equivalent carbon number, while the retention in silver-ion chromatography increases with the increasing number of DBs with a clear differentiation between cis - and trans- FAs. Moreover, silver-ion mode enables at least the partial resolution of regioisomeric TG mixtures including cis -/trans -regioisomers, as illustrated on two examples of randomization mixtures. Off-line 2D coupling of both complementary modes (NARP in the first dimension and silver-ion in the second dimension) yields the superior chromatographic selectivity resulting in the highest number of identified TGs ever reported for studied samples. Off-line 2D chromatograms are processed with the home-made software providing various ways of data visualization. [source] Disorderly reasoning in information designJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 9 2009Peter Hall The importance of information visualization as a means of transforming data into visual, understandable form is now embraced across university campuses and research institutes world-wide. Yet, the role of designers in this field of activity is often overlooked by the dominant scientific and technological interests in data visualization, and a corporate culture reliant on off-the-shelf visualization tools. This article is an attempt to describe the value of design thinking in information visualization with reference to Horst Rittel's (1988) definition of "disorderly reasoning," and to frame design as a critical act of translating between scientific, technical, and aesthetic interests. [source] Surface Laser Scanning of Fossil Insect WingsPALAEONTOLOGY, Issue 1 2004Olivier Béthoux Primary homologization of wing venation is of crucial importance in taxonomic studies of fossil and recent insects, with implications for large-scale phylogenies. Homologization is usually based on relative relief of veins (with an insect ground plan of alternating concave and convex vein sectors). However, this method has led to divergent interpretations, notably because vein relief can be attenuated in fossil material or because wings were originally flat. In order to interpret better vein relief in fossil insect wings, we tested the application of non-contact laser scanning. This method enables high resolution three-dimensional (3-D) data visualization of a surface, and produces high quality images of fossil insect wings. These images facilitate and improve interpretation of the homologization of wing venation. In addition, because the surface information is digitised in three axes (X, Y, Z), the data may be processed for a wide range of surface characteristics, and may be easily and widely distributed electronically. Finally, this method permits users to reconstruct accurately the fossils and opens the field of biomechanical interpretation using numerical modelling methods. [source] Development and validation of a spectral library searching method for peptide identification from MS/MSPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 5 2007Henry Lam Abstract A notable inefficiency of shotgun proteomics experiments is the repeated rediscovery of the same identifiable peptides by sequence database searching methods, which often are time-consuming and error-prone. A more precise and efficient method, in which previously observed and identified peptide MS/MS spectra are catalogued and condensed into searchable spectral libraries to allow new identifications by spectral matching, is seen as a promising alternative. To that end, an open-source, functionally complete, high-throughput and readily extensible MS/MS spectral searching tool, SpectraST, was developed. A high-quality spectral library was constructed by combining the high-confidence identifications of millions of spectra taken from various data repositories and searched using four sequence search engines. The resulting library consists of over 30,000 spectra for Saccharomyces cerevisiae. Using this library, SpectraST vastly outperforms the sequence search engine SEQUEST in terms of speed and the ability to discriminate good and bad hits. A unique advantage of SpectraST is its full integration into the popular Trans Proteomic Pipeline suite of software, which facilitates user adoption and provides important functionalities such as peptide and protein probability assignment, quantification, and data visualization. This method of spectral library searching is especially suited for targeted proteomics applications, offering superior performance to traditional sequence searching. [source] Detection of artifacts and peptide modifications in liquid chromatography/mass spectrometry data using two-dimensional signal intensity map data visualizationRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 10 2006Matthias Berg We demonstrate how visualization of liquid chromatography/mass spectrometry data as a two-dimensional signal intensity map can be used to assess the overall quality of the data, for the identification of polymer contaminants and artifacts, as well as for the confirmation of post-translational modifications. Copyright © 2006 John Wiley & Sons, Ltd. [source] Analysis of call centre arrival data using singular value decompositionAPPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, Issue 3 2005Haipeng Shen Abstract We consider the general problem of analysing and modelling call centre arrival data. A method is described for analysing such data using singular value decomposition (SVD). We illustrate that the outcome from the SVD can be used for data visualization, detection of anomalies (outliers), and extraction of significant features from noisy data. The SVD can also be employed as a data reduction tool. Its application usually results in a parsimonious representation of the original data without losing much information. We describe how one can use the reduced data for some further, more formal statistical analysis. For example, a short-term forecasting model for call volumes is developed, which is multiplicative with a time series component that depends on day of the week. We report empirical results from applying the proposed method to some real data collected at a call centre of a large-scale U.S. financial organization. Some issues about forecasting call volumes are also discussed. Copyright © 2005 John Wiley & Sons, Ltd. [source] Aspects of magnetic data processingARCHAEOLOGICAL PROSPECTION, Issue 4 2001M. Ciminale Abstract The presence of noisy contributions such as spikes, stripes and zigzag effects in magnetic data visualization represents the most common flaw that may degrade the image, rendering the correct detection and identification of archaeological features very uncertain. In order to overcome this serious disadvantage, a software package has been developed by implementing very simple algorithms based on statistical criteria. Some applications to field data are shown and discussed in order to demonstrate the program's ability to remove or minimize these undesired contributions. The results are very satisfactory: high-quality digital raster images may be produced. Copyright © 2001 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||