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Articles 1591 - 1620 of 2496

Full-Text Articles in Physical Sciences and Mathematics

Relationships Between Erodibility And Fine-Grained Seabed Properties On Tidal To Seasonal Time-Scales, York River Estuary, Virginia, Usa, Lindsey M. Kraatz, Carl T. Friedrichs, Grace M. Cartwright, Kelsey A. Fall Aug 2012

Relationships Between Erodibility And Fine-Grained Seabed Properties On Tidal To Seasonal Time-Scales, York River Estuary, Virginia, Usa, Lindsey M. Kraatz, Carl T. Friedrichs, Grace M. Cartwright, Kelsey A. Fall

Presentations

No abstract provided.


Controls On Particle Settling Velocity And Bed Erodibility In The Presence Of Muddy Flocs And Pellets As Inferred By Advs, York River Estuary, Virginia, Usa, Kelsey A. Fall, Carl T. Friedrichs, Grace M. Cartwright Aug 2012

Controls On Particle Settling Velocity And Bed Erodibility In The Presence Of Muddy Flocs And Pellets As Inferred By Advs, York River Estuary, Virginia, Usa, Kelsey A. Fall, Carl T. Friedrichs, Grace M. Cartwright

Presentations

No abstract provided.


Damping Of Turbulence By Suspended Sediment: Ramifications Of Under-Saturated, Critically-Saturated, And Over-Saturated Conditions, Carl T. Friedrichs Aug 2012

Damping Of Turbulence By Suspended Sediment: Ramifications Of Under-Saturated, Critically-Saturated, And Over-Saturated Conditions, Carl T. Friedrichs

Presentations

No abstract provided.


Cosmic Ray Particles Images With Orca-Ii Erg, George Mcnamara Aug 2012

Cosmic Ray Particles Images With Orca-Ii Erg, George Mcnamara

George McNamara

Cosmic ray particles image series acquired using a Hamamatsu ORCA-II ERG scientific grade CCD camera, cooled to -60 C. Each image is a consecutive 600 second (10 minute) exposure time with no light to the camera.

While processing the data, I discoverd that the background changed around planes 25 and 227 (see Excel file and jpeg screenshots), so I also processed only planes 025-227 (203 planes total, 2030 minutes, 33.83 hours). the CCD industry "rule of thumb" for a "typical" CCD sensor (i.e. 1/3" CCD) is that one cosmic ray particle strikes a sensor approximately every 30 seconds (assuming not …


A Homogeneous Solution Of The Einstein-Maxwell Equations, Charles G. Torre Jul 2012

A Homogeneous Solution Of The Einstein-Maxwell Equations, Charles G. Torre

Research Vignettes

We exhibit and analyze a homogeneous spacetime whose source is a pure radiation electromagnetic field [1]. It was previously believed that this spacetime is the sole example of a homogeneous pure radiation solution of the Einstein equations which admits no electromagnetic field (see [2] and references therein). Here we correct this error in the literature by explicitly displaying the electromagnetic source. This result implies that all homogeneous pure radiation spacetimes satisfy the Einstein-Maxwell equations.

PDF and Maple worksheets can be downloaded from the links below.


Deep Silicate Absorption Features In Compton-Thick Active Galactic Nuclei Predominantly Arise Due To Dust In The Host Galaxy, A. D. Goulding, D. M. Alexander, F. E. Bauer, W. R. Forman, R. C. Hickox Jul 2012

Deep Silicate Absorption Features In Compton-Thick Active Galactic Nuclei Predominantly Arise Due To Dust In The Host Galaxy, A. D. Goulding, D. M. Alexander, F. E. Bauer, W. R. Forman, R. C. Hickox

Dartmouth Scholarship

We explore the origin of mid-infrared (mid-IR) dust extinction in all 20 nearby (z < 0.05) bona fide Compton-thick (N H > 1.5 × 1024 cm–2) active galactic nuclei (AGNs) with hard energy (E > 10 keV) X-ray spectral measurements. We accurately measure the silicate absorption features at λ ~ 9.7 μm in archival low-resolution (R ~ 57-127) Spitzer Infrared Spectrograph spectroscopy, and show that only a minority (≈45%) of nearby Compton-thick AGNs have strong Si-absorption features (S 9.7 = ln (f int/f obs) 0.5) which would indicate significant dust attenuation. The majority (≈60%) are star …


How To Create A Lie Algebra, Ian M. Anderson Jul 2012

How To Create A Lie Algebra, Ian M. Anderson

How to... in 10 minutes or less

We show how to create a Lie algebra in Maple using three of the most common approaches: matrices, vector fields and structure equations. PDF and Maple worksheets can be downloaded from the links below.


Starcraft Ii In-Game Action Lists, Gong Wei, Ee Peng Lim, Achananuparp Palakorn, Feida Zhu, David Lo, Freddy Chua Jun 2012

Starcraft Ii In-Game Action Lists, Gong Wei, Ee Peng Lim, Achananuparp Palakorn, Feida Zhu, David Lo, Freddy Chua

SMU Research Data

1732 event logs of actions performed by players in Starcraft II public replays downloaded from GameReplays.org.

The Data Set consists of 1732 log files (Size: 55 MB) compressed into a Zip archive (Size: 9.3 MB).

This dataset has accumulated 267 downloads from 19 July 2012 to 2 Nov 2017 before being transferred to another collection.

Old URL: http://ink.library.smu.edu.sg/data/1/


Delayed Observation Planning In Partially Observable Domains, Pradeep Reddy Varakantham, Janusz Marecki Jun 2012

Delayed Observation Planning In Partially Observable Domains, Pradeep Reddy Varakantham, Janusz Marecki

Research Collection School Of Computing and Information Systems

Traditional models for planning under uncertainty such as Markov Decision Processes (MDPs) or Partially Observable MDPs (POMDPs) assume that the observations about the results of agent actions are instantly available to the agent. In so doing, they are no longer applicable to domains where observations are received with delays caused by temporary unavailability of information (e.g. delayed response of the market to a new product). To that end, we make the following key contributions towards solving Delayed observation POMDPs (D-POMDPs): (i) We first provide an parameterized approximate algorithm for solving D-POMDPs efficiently, with desired accuracy; and (ii) We then propose …


Glme3_Ado_Do_Files, Joseph Hilbe May 2012

Glme3_Ado_Do_Files, Joseph Hilbe

Joseph M Hilbe

GLME3 ado and do files (116 in total)


Combining Observational And Numerical Model Results To Improve Estimates Of Hypoxic Volume In Chesapeake Bay, A. J. Bever, Marjorie A.M. Friedrichs, Carl T. Friedrichs, M. E. Scully May 2012

Combining Observational And Numerical Model Results To Improve Estimates Of Hypoxic Volume In Chesapeake Bay, A. J. Bever, Marjorie A.M. Friedrichs, Carl T. Friedrichs, M. E. Scully

Presentations

No abstract provided.


Ambiguous Data Association And Entangled Attribute Estimation, Randy Paffenroth, David Trawick, Philip Du Toit, Gregory Norgard May 2012

Ambiguous Data Association And Entangled Attribute Estimation, Randy Paffenroth, David Trawick, Philip Du Toit, Gregory Norgard

Randy C. Paffenroth

This paper presents an approach to attribute estimation incorporating data association ambiguity. In modern tracking systems, time pressures often leave all but the most likely data association alternatives unexplored, possibly producing track inaccuracies. Numerica's Bayesian Network Tracking Database, a key part of its Tracker Adjunct Processor, captures and manages the data association ambiguity for further analysis and possible ambiguity reduction/resolution using subsequent data. Attributes are non-kinematic discrete sample space sensor data. They may be as distinctive as aircraft ID, or as broad as friend or foe. Attribute data may provide improvements to data association by a process known as Attribute …


Detecting Clustered Chem/Bio Signals In Noisy Sensor Feeds Using Adaptive Fusion, Randy Paffenroth, Scott Lundberg, Chris Calderon May 2012

Detecting Clustered Chem/Bio Signals In Noisy Sensor Feeds Using Adaptive Fusion, Randy Paffenroth, Scott Lundberg, Chris Calderon

Randy C. Paffenroth

Chemical and biological monitoring systems are faced with the challenge of detecting weak signals from contam- inants of interest while at the same time maintaining extremely low false alarm rates. We present methods to control the number of false alarms while maintaining power to detect; evaluating these methods on a fixed sensor grid. Contaminants are detected using signals produced from underlying sensor-specific detection algorithms. By learning from past data, an adaptive background model is constructed and used with a multi-hypothesis testing method to control the false alarm rate. Detection methods for chemical/biological releases often depend on specific models for release …


Distributed Pattern Detection In Cyber Networks, Randy Paffenroth, Philip Du Toit, Louis Scharf, Anura Jayasumana, Vidarshana Banadara, Ryan Nong May 2012

Distributed Pattern Detection In Cyber Networks, Randy Paffenroth, Philip Du Toit, Louis Scharf, Anura Jayasumana, Vidarshana Banadara, Ryan Nong

Randy C. Paffenroth

In this paper we describe an approach for the detection and classication of weak, distributed patterns in sensor networks. Of course, before one can begin development of a pattern detection algorithm, one must rst dene the term "pattern", which by nature is a broad and inclusive term. One of the key aspects of our work is a denition of pattern that has already proven eective in detecting anomalies in real world data. While designing detection algorithms for all classes of patterns in all types of networks sounds appealing, this approach would almost certainly require heuristic methods and only cursory statements …


Spatial And Temporal Trends In Tidal Flat Shape In San Francisco Bay, J. A. Bearman, Carl T. Friedrichs, B. E. Jaffe, A. C. Foxgrover Apr 2012

Spatial And Temporal Trends In Tidal Flat Shape In San Francisco Bay, J. A. Bearman, Carl T. Friedrichs, B. E. Jaffe, A. C. Foxgrover

Presentations

No abstract provided.


1112+3548_Nir_Spex, J. Patience Apr 2012

1112+3548_Nir_Spex, J. Patience

Publications and Research

No abstract provided.


Clay Fabric And Mass Physical Properties Of Surficial Marine Sediment Near The Deepwater Horizon Oil Spill, Andrew Head, Richard H. Bennett, Jessica R. Douglas, Kenneth J. Curry Feb 2012

Clay Fabric And Mass Physical Properties Of Surficial Marine Sediment Near The Deepwater Horizon Oil Spill, Andrew Head, Richard H. Bennett, Jessica R. Douglas, Kenneth J. Curry

Kenneth J. Curry

Surficial sediment was obtained on the RV Cape Hatteras Cruise (2010) from the seafloor at a water depth of 1570 meters located at latitude 28°44'20.16"N and longitude 88°20'24.96"W in close proximity to the Deepwater Horizon well, Gulf of Mexico. Preliminary clay nano- and microfabric observation using a transmission electron microscope (TEM) depicted a sediment rich in clays and organic matter (OM) especially in the upper 2 cm subbottom. Initial analysis of TEM micrographs depicted a high porosity clay sediment. Initial study of the mass physical properties revealed water content ωt = 67.32 – 67.28% (percent total mass), porosity n= 84.1 …


Results Of The Us Ioos Testbed For Comparison Of Hydrodynamic And Dissolved Oxygen Models Of The Chesapeake Bay, M.A.M. Friedrichs, A. J. Bever, M. E. Scully, W. Long Feb 2012

Results Of The Us Ioos Testbed For Comparison Of Hydrodynamic And Dissolved Oxygen Models Of The Chesapeake Bay, M.A.M. Friedrichs, A. J. Bever, M. E. Scully, W. Long

Presentations

Results from multiple 3-D hydrodynamic and dissolved oxygen models for Chesapeake Bay have been compared to each other and to EPA monitoring data for the years 2004 and 2005. On seasonal time-scales, the models all do well in capturing fundamental aspects of the hydrodynamic and oxygen fields, although the intensity of the pycnocline is underestimated. Models with constant net respiration independent of nutrient supply reproduce hypoxia nearly as well as much more complex, nutrient-dependent ecological models. Seasonal variation in DO was insensitive to seasonal cycles in the respiration rate, freshwater input, and density stratification. Rather, seasonal variation in DO was …


Use Of Acoustic Doppler Velocimeters (Advs) To Infer Relationships Among Fine Sediment Settling, Bed Erodibility And Particle Type, York River Estuary, Va, K. A. Fall, Carl T. Friedrichs, Grace M. Cartwright Feb 2012

Use Of Acoustic Doppler Velocimeters (Advs) To Infer Relationships Among Fine Sediment Settling, Bed Erodibility And Particle Type, York River Estuary, Va, K. A. Fall, Carl T. Friedrichs, Grace M. Cartwright

Presentations

Bed erodibility and particle settling velocity are key factors influencing fine sediment dynamics in coastal and estuarine environments. In order to better constrain inherently complex, temporally-varying relationships among hydrodynamics, bed properties and particle types, near-bed ADVs have been maintained in the York River Estuary since 2006. The ADVs provide measurements of bottom stress, suspended sediment concentration (C, via calibrated backscatter), and particle settling velocity (Ws, via a Rouse balance). By assuming Ws to be the combined result of rapidly settling fecal pellets plus more slowly settling flocs, the time-varying fraction of pellets versus flocs can be estimated. Vertical integration of …


Dual Use Of A Sediment Mixing Tank For Calibrating Acoustic Backscatter And Direct Doppler Measurement Of Settling Velocity, Grace M. Cartwright, Carl T. Friedrichs, P. D. Panetta Feb 2012

Dual Use Of A Sediment Mixing Tank For Calibrating Acoustic Backscatter And Direct Doppler Measurement Of Settling Velocity, Grace M. Cartwright, Carl T. Friedrichs, P. D. Panetta

Presentations

While the Acoustic Doppler Velocimeter (ADV) is designed to determine fluid velocity, it is important to recognize that it is actually the velocity of the scatterers themselves that is measured. Thus in a calibration tank designed to relate sediment-induced backscatter to sediment concentration, the vertical velocity registered by an ADV at a given point is actually the true fluid velocity plus the sediment’s settling velocity. And absent net vertical volume flux, the average vertical velocity registered by an ADV across a horizontal plane is equal to the mean sediment settling velocity. For this study, a series of ADV calibrations were …


Relationships Between Erodibility And Fine-Grained Seabed Properties On Tidal To Seasonal Time-Scales, York River Estuary, Virginia, L. M. Kraatz, Carl T. Friedrichs, Grace M. Cartwright, K. A. Fall Feb 2012

Relationships Between Erodibility And Fine-Grained Seabed Properties On Tidal To Seasonal Time-Scales, York River Estuary, Virginia, L. M. Kraatz, Carl T. Friedrichs, Grace M. Cartwright, K. A. Fall

Presentations

The complex bio-geo-physical nature of muddy particles in coastal and estuarine environments has limited our understanding of finegrained sediment dynamics. An ongoing sedimentalogical study within the York River Estuary is investigating controls on cohesive bed erodibility by assessing changes in seabed properties over varying timescales. During the spring and summer of 2010 and 2011, multiple GOMEX box cores were collected and subsampled for grain size, fecal pellet content, Gust chamber erodibility, and water content. Initial findings suggest that erodibility of the seabed increased during periods following seasonal deposition events. Higher erodibility was also generally found to coincide with peak spring …


Open Source Classroom Polling (Interactive Response) Facility, Ronald I. Greenberg Feb 2012

Open Source Classroom Polling (Interactive Response) Facility, Ronald I. Greenberg

Computer Science: Faculty Publications and Other Works

The contents of the UNIX directory resulting from unzipping the .zip file provide a demonstration of a simple polling facililty that instructors can use in class any time that students have access to a web browser. This is a good way to have students work problems and see to what extent they are converging towards correct answers.

Unlike other polling facilities, this one is completely free without any restrictions on number of simultaneous users, etc. It also allows a feature most polling facilities do not in that it may be used for completely free-form answers, and the instructor can still …


R Code: A Non-Iterative Implementation Of Tango's Score Confidence Interval For A Paired Difference Of Proportions, Zhao Yang Jan 2012

R Code: A Non-Iterative Implementation Of Tango's Score Confidence Interval For A Paired Difference Of Proportions, Zhao Yang

Zhao (Tony) Yang, Ph.D.

For matched-pair binary data, a variety of approaches have been proposed for the construction of a confidence interval (CI) for the difference of marginal probabilities between two procedures. The score-based approximate CI has been shown to outperform other asymptotic CIs. Tango’s method provides a score CI by inverting a score test statistic using an iterative procedure. In the developed R code, we propose an efficient non-iterative method with closed-form expression to calculate Tango’s CIs. Examples illustrate the practical application of the new approach.


Gis Data: City Of Virginia Beach, Virginia Tidal Marsh Inventory, Marcia Berman, Harry Berquist, Sharon A. Killeen, Carl Hershner, Karinna Nunez, Karen Reay, Tamia Rudnicky, Daniel E. Schatt Jan 2012

Gis Data: City Of Virginia Beach, Virginia Tidal Marsh Inventory, Marcia Berman, Harry Berquist, Sharon A. Killeen, Carl Hershner, Karinna Nunez, Karen Reay, Tamia Rudnicky, Daniel E. Schatt

Data

The 2012 Tidal Marsh Inventory update for Virginia Beach, VA was generated using on-screen digitizing techniques in the most recent version of ArcGIS® - ArcMap while viewing conditions observed in the most recent imagery from the Virginia Base Mapping Program (VBMP). Dominant plant community types were primarily determined during field surveys from shallow-draft boats moving along the shoreline. Land-based surveys were performed in some locations. One shapefile is developed that portrays tidal marsh areas represented as polygons. A metadata file accompanies the shapefile to define attribute accuracy, data development, and any use restrictions that pertain to the data.


Gis Data: City Of Fairfax County, Virginia Tidal Marsh Inventory, Marcia Berman, Harry Berquist, Sharon Killeen, Carl Hershner, Karinna Nunez, Karen Reay, Tamia Rudnicky Jan 2012

Gis Data: City Of Fairfax County, Virginia Tidal Marsh Inventory, Marcia Berman, Harry Berquist, Sharon Killeen, Carl Hershner, Karinna Nunez, Karen Reay, Tamia Rudnicky

Data

The 2012 Tidal Marsh Inventory update for Fairfax County, Virginia was generated using on-screen digitizing techniques in the most recent version of ArcGIS® - ArcMap while viewing conditions observed in the most recent imagery from the Virginia Base Mapping Program (VBMP). Dominant plant community types were primarily determined during field surveys from shallow-draft boats moving along the shoreline. Land-based surveys were performed in some locations. One shapefile is developed that portrays tidal marsh areas represented as polygons. A metadata file accompanies the shapefile to define attribute accuracy, data development, and any use restrictions that pertain to the data.


Evaluating The Benefits Of Octree-Based Indexing For Lidar Data, Abu Saleh Mohammad Mosa, Bianca Schoen-Phelan, Michela Bertolotto, Debra Laefer Jan 2012

Evaluating The Benefits Of Octree-Based Indexing For Lidar Data, Abu Saleh Mohammad Mosa, Bianca Schoen-Phelan, Michela Bertolotto, Debra Laefer

Articles

Very large true three-dimensional (3D) point datasets, as opposed to the previously common 2.5D data sets, are progressively more common nowadays, such as from Light Detection and Ranging (LiDAR). Increasingly, attempts are made to exploit these 3D point data sets beyond mere visualization. However, current Spatial Information Systems provide only limited 3D support. Even commercial systems advertising in-built, 3D data types provide only minimal functionality. Particularly, there is no effective means of indexing large 3D point datasets, which is crucial for efficient analysis and engineering usage. Also many datasets are information rich (e.g. contain color or some other associated semantic …


Improving Quality Of Service In Xml Data Stream Processing Using Load Shedding, Ranjan Dash Jan 2012

Improving Quality Of Service In Xml Data Stream Processing Using Load Shedding, Ranjan Dash

Computer Science and Engineering Dissertations

In recent years, we have witnessed the emergence of new types of systems that deal with large volumes of streaming data. Examples include nancial data analy- sis on feeds of stock tickers, sensor-based environmental monitoring, network tra c monitoring and click stream analysis to push customized advertisements or intrusion detection. Traditional database management systems (DBMS), which are very good at managing large volumes of stored data, fall short of serving this new class of appli- cations, which require low-latency processing on live data from push-based sources. Data Stream Management Systems (DSMS) are fast emerging to address this new type of …


An Extensible Self-Adapting Dissemination Framework For High-Speed Continuous Xml Streaming Data, Anthony E. Okorodudu Jan 2012

An Extensible Self-Adapting Dissemination Framework For High-Speed Continuous Xml Streaming Data, Anthony E. Okorodudu

Computer Science and Engineering Dissertations

The efficient dissemination of data has become increasingly important with recent advances in technology that provide us immediate access to information at our fingertips. The insatiable demand for data has increased significantly with the popularity and widespread use of smart phones and tablets throughout the world. This thesis is focused on efficient push-based means of disseminating data to a large number of interested clients using a network of co-operating machines, called brokers.There have been extensive studies in optimizing both XML filtering and XPath-based subscription management in publish/subscribe systems with the aim of disseminating data in a timely fashion. Much less …


Gis Data: City Of Alexandria Tidal Marsh Inventory, Marcia Berman, Harry Berquist, Sharon Killeen, Carl Hershner, Karinna Nunez, Karen Reay, Tamia Rudnicky Jan 2012

Gis Data: City Of Alexandria Tidal Marsh Inventory, Marcia Berman, Harry Berquist, Sharon Killeen, Carl Hershner, Karinna Nunez, Karen Reay, Tamia Rudnicky

Data

The 2012 Tidal Marsh Inventory update for City of Alexandria, Virginia was generated using on-screen digitizing techniques in the most recent version of ArcGIS® - ArcMap while viewing conditions observed in the most recent imagery from the Virginia Base Mapping Program (VBMP). Dominant plant community types were primarily determined during field surveys from shallow-draft boats moving along the shoreline. Land-based surveys were performed in some locations. One shapefile is developed that portrays tidal marsh areas represented as polygons. A metadata file accompanies the shapefile to define attribute accuracy, data development, and any use restrictions that pertain to the data.


A New Integrative Data Mining Framework For Analyzing The Cancer Genome Atlas Data, Dijun Luo Jan 2012

A New Integrative Data Mining Framework For Analyzing The Cancer Genome Atlas Data, Dijun Luo

Computer Science and Engineering Dissertations

Besides accuracy and efficiency, understandability is another key issue of predictive modeling in real-world applications, especially in biomedical and healthcare data analysis. We develop a new integrative framework to enhance the interpretability of data by sparsity-based learning. We proposed several novel sparsity-based learning models, emphasizing different understandable properties of data, such as explicit sparsity, low redundancy, and low rank, and apply to The Cancer Genome Atlas (TCGA) data analysis. Results indicate that the proposed methods provide more insights from TCGA data while maintaining stable and competitive performances in predictive modeling. To further enhance the interpretability of biological processes and disease …