Algorithms

Expected Performance of the ATLAS Experiment – Detector, Trigger and Physics. DE20121030553

by

Personal Author Aad, G.; Abat, E.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.
The Large Hadron Collider (LHC) at CERN promises a major step forward in the understanding of the fundamental nature of matter. The ATLAS experiment is a general-purpose detector for the LHC, whose design was guided by the need to accommodate the wide spectrum of possible physics signatures. The major remit of the ATLAS experiment is the exploration of the TeV mass scale where groundbreaking discoveries are expected. In the focus are the investigation of the electroweak symmetry breaking and linked to this the search for the Higgs boson as well as the search for Physics beyond the Standard Model. In this report a detailed examination of the expected performance of the ATLAS detector is provided, with a major aim being to investigate the experimental sensitivity to a wide range of measurements and potential observations of new physical processes. An earlier summary of the expected capabilities of ATLAS was compiled in 1999 (1). A survey of physics capabilities of the CMS detector was published in (2). The design of the ATLAS detector has now been finalised, and its construction and installation have been completed (3). An extensive test-beam programme was undertaken. Furthermore, the simulation and reconstruction software code and frameworks have been completely rewritten. Revisions incorporated reflect improved detector modelling as well as major technical changes to the software technology. Greatly improved understanding of calibration and alignment techniques, and their practical impact on performance, is now in place. The studies reported here are based on full simulations of the ATLAS detector response.
For more info please contact NTIS 1-800-553-6847 Mon – Fri 8am – 5pm est
NTRLlogo3[1]

Optimization of Water-Level Monitoring Networks in the Eastern Snake River Plain Aquifer Using a Kriging-Based Genetic Algorithm Method. PB2014104612

by

Long-term groundwater monitoring networks can provide essential information for the planning and management of water resources. Budget constraints in water resource management agencies often mean a reduction in the number of observation wells included in a monitoring network. A network design tool, distributed as an R package, was developed to determine which wells to exclude from a monitoring network because they add little or no beneficial information. A kriging-based genetic algorithm method was used to optimize the monitoring network. The algorithm was used to find the set of wells whose removal leads to the smallest increase in the weighted sum of the (1) mean standard error at all nodes in the kriging grid where the water table is estimated, (2) root-mean-squared-error between the measured and estimated water-level elevation at the removed sites, (3) mean standard deviation of measurements across time at the removed sites, and (4) mean measurement error of wells in the reduced network. The solution to the optimization problem (the best wells to retain in the monitoring network) depends on the total number of wells removed; this number is a management decision.
Personal Author Fisher, J. C.
For more information please contact NTIS 1-800-553-6847 Mon -Fri 8am – 5pm est or go to www.ntis.gov
NTRLlogo3[1]

Mining Tera-Scale Graphs: Theory, Engineering and Discoveries

by

images[2]How do we find patterns and anomalies, on graphs with billions of nodes and edges which do not fit in memory. How to use parallelism for such Tera- or Peta-scale graphs. In this thesis, we propose PEGASUS, a large scale graph mining system implemented on the top of the HADOOP platform, the open source version of MAPREDUCE. PEGASUS includes algorithms which help us spot patterns and anomalous behaviors in large graphs. PEGASUS enables the structure analysis on large graphs. We unify many different structure analysis algorithms, including the analysis on connected components, PageRank, and radius/diameter, into a general primitive called GIM-V. GIM-V is highly optimized, achieving good scale-up on the number of edges and available machines. We discover surprising patterns using GIM-V, including the 7-degrees of separation in one of the largest publicly available Web graphs, with 7 billion edges. PEGASUS also enables the inference and the spectral analysis on large graphs. We design an efficient distributed belief propagation algorithm which infer the states of unlabeled nodes given a set of labeled nodes. We also develop an eigensolver for computing top k eigenvalues and eigenvectors of the adjacency matrices of very large graphs. We use the eigensolver to discover anomalous adult advertisers in the who-follows-whom Twitter graph with 3 billion edges. In addition, we develop an efficient tensor decomposition algorithm and use it to analyze a large knowledge base tensor. Finally, PEGASUS allows the management of large graphs. We propose efficient graph storage and indexing methods to answer graph mining queries quickly. We also develop an edge layout algorithm for better compressing graphs.
Personal Author U. Kang
For more info go to: http://www.ntis.gov/search/product.aspx?ABBR=ADA562174 or call NTIS 1-800-553-6847 8am – 5pm Mon – Fri est

Generalized Framework and Algorithms for Illustrative Visualization of Time-Varying Data on Unstructured Meshes

by

images[1]Photo- and physically-realistic techniques are often insufficient for visualization of simulation results, especially for three-dimensional and timevarying datasets. Substantial research efforts have been dedicated to the development of nonphoto-realistic and illustration-inspired visualization techniques for compact and intuitive presentation of such complex datasets. While these efforts have yielded valuable visualization results, a great deal of work has been reproduced in studies as individual research groups often develop purpose-built platforms. Additionally, interoperability between illustrative visualization software is limited because of specialized processing and rendering architectures employed in different studies. This report proposes a generalized framework for illustrative visualization and implements it in MarmotViz, a ParaView plug-in, enabling its use on a variety of computing platforms with various data file formats and mesh geometries. This report gives detailed descriptions of the region-of-interest identification and feature-tracking algorithms incorporated into this tool. Implementations of multiple illustrative effect algorithms are presented to demonstrate the use and flexibility of this framework. By providing a framework and useful underlying functionality, the MarmotViz tool can act as a springboard for future research in the field of illustrative visualization. Personal Author A. Joshi A. S. Rattner D. P. Guillen S. Garimella
Personal Author A. Joshi A. S. Rattner D. P. Guillen S. Garimella