Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

179,641 Full-Text Articles 219,000 Authors 37,243,081 Downloads 384 Institutions

All Articles in Physical Sciences and Mathematics

Faceted Search

179,641 full-text articles. Page 4234 of 4637.

Energy Balanced Routing Strategy In Wireless Sensor Networks, Xiaoguang Zhang, Zheng da Wu 2010 Bond University

Energy Balanced Routing Strategy In Wireless Sensor Networks, Xiaoguang Zhang, Zheng Da Wu

Information Technology papers

In order to tackle the energy hole problem of sensor networks, the non-uniform node deployment strategy was presented recently. For achieving the expected performance of this deployment method, nodes need to transmit data to the sink node through selecting a node in the adjacent inner-region decided by the deployment strategy. Since nodes near the outerboundary of a region will be covered by more nodes, the random selection method will cause the unbalanced energy consumption problem. In this paper, this issue is rigorously studied and a region constrained selection scheme is proposed based on the analytical result. Numerical and simulation results ...


Nanoparticle Doped Photopolymer With Reduced Shrinkage For Holographic Recording, Mohesh Moothanchery, Svetlana Mintova, Izabela Naydenova, Vincent Toal 2010 Dublin Institute of Technology

Nanoparticle Doped Photopolymer With Reduced Shrinkage For Holographic Recording, Mohesh Moothanchery, Svetlana Mintova, Izabela Naydenova, Vincent Toal

Conference Papers

We demonstrate holographic recording with Si-MFI zeolite doped acrylamide based photopolymerfilm. The influence of silicate nanoparticles on photopolymer shrinkage has been studied and compared withshrinkage in undoped photopolymer layers The shrinkage of the material (1.03%) is significantly lower forrecording in Si-MFI zeolite nanoparticle doped samples than for undoped layers (1.77%).


Fast Query Processing By Distributing An Index Over Cpu Caches, Xiaoqin Ma, Gene D. Cooperman 2010 Northeastern University

Fast Query Processing By Distributing An Index Over Cpu Caches, Xiaoqin Ma, Gene D. Cooperman

Gene D. Cooperman

Data intensive applications on clusters often require requests quickly be sent to the node managing the desired data. In many applications, one must look through a sorted tree structure to determine the responsible node for accessing or storing the data. Examples include object tracking in sensor networks, packet routing over the internet, request processing in publish-subscribe middleware, and query processing in database systems. When the tree structure is larger than the CPU cache, the standard implementation potentially incurs many cache misses for each lookup; one cache miss at each successive level of the tree. As the CPURAM gap grows, this ...


Air Shower Simulation Using Geant4 And Commodity Parallel Computing, L. Anchordoqui, G. Cooperman, V. Grinberg, T. McCauley, T. Paul, S. Reucroft, J. Swain, G. Alverson 2010 Northeastern University

Air Shower Simulation Using Geant4 And Commodity Parallel Computing, L. Anchordoqui, G. Cooperman, V. Grinberg, T. Mccauley, T. Paul, S. Reucroft, J. Swain, G. Alverson

Gene D. Cooperman

We present an evaluation of a simulated cosmic ray shower, based on GEANT4 and TOP-C, which tracks all the particles in the shower. TOP-C (Task Oriented Parallel C) provides a framework for parallel algorithm development which makes tractable the problem of following each particle. This method is compared with a simulation program which employs the Hillas thinning algorithm.


End Of Year Report : Fy 2005, Gene Cooperman 2010 Northeastern University

End Of Year Report : Fy 2005, Gene Cooperman

Gene D. Cooperman

No abstract provided.


Geant4 Developments And Applications, J. Allison, K. Amako, J. Apostolakis, H. Araujo, P. Arce Dubois, M. Asai, G. Barrand, R. Capra, S. Chauvie, R. Chytracek, G. A. P. Cirrone, Gene D. Cooperman, G. Cosmo, G. Cuttone, G. G. Daquino, M. Donszelmann, M. Dressel, G. Folger, F. Foppiano, J. Generowicz, V. Grichine, S. Guatelli, P. Gumplinger, A. Heikkinen, I. Hrivnacova, A. Howard, S. Incerti, V. Ivanchenko, T. Johnson, F. Jones, T. Koi, R. Kokoulin, M. Kossov, H. Kurashige, V. Lara, S. Larsson, F. Lei, O. Link, F. Longo, M. Maire, A. Mantero, B. Mascialino, I. McLaren, P. Mendez Lorenzo, K. Minamimoto, K. Murakami, P. Nieminen, L. Pandola, S. Parlati, L. Peralta, J. Perl, A. Pfeiffer, M. G. Pia, A. Ribon, P. Rodrigues, G. Russo, S. Sadilov, G. Santin, T. Sasaki, D. Smith, N. Starkov, S. Tanaka, E. Tcherniaev, B. Tomé, A. Trindade, P. Truscott, L. Urban, M. Verderi, A. Walkden, J. P. Wellisch, D. C. Williams, D. Wright, H. Yoshida 2010 Northeastern University

Geant4 Developments And Applications, J. Allison, K. Amako, J. Apostolakis, H. Araujo, P. Arce Dubois, M. Asai, G. Barrand, R. Capra, S. Chauvie, R. Chytracek, G. A. P. Cirrone, Gene D. Cooperman, G. Cosmo, G. Cuttone, G. G. Daquino, M. Donszelmann, M. Dressel, G. Folger, F. Foppiano, J. Generowicz, V. Grichine, S. Guatelli, P. Gumplinger, A. Heikkinen, I. Hrivnacova, A. Howard, S. Incerti, V. Ivanchenko, T. Johnson, F. Jones, T. Koi, R. Kokoulin, M. Kossov, H. Kurashige, V. Lara, S. Larsson, F. Lei, O. Link, F. Longo, M. Maire, A. Mantero, B. Mascialino, I. Mclaren, P. Mendez Lorenzo, K. Minamimoto, K. Murakami, P. Nieminen, L. Pandola, S. Parlati, L. Peralta, J. Perl, A. Pfeiffer, M. G. Pia, A. Ribon, P. Rodrigues, G. Russo, S. Sadilov, G. Santin, T. Sasaki, D. Smith, N. Starkov, S. Tanaka, E. Tcherniaev, B. Tomé, A. Trindade, P. Truscott, L. Urban, M. Verderi, A. Walkden, J. P. Wellisch, D. C. Williams, D. Wright, H. Yoshida

Gene D. Cooperman

Geant4 is a software toolkit for the simulation of the passage of particles through matter. It is used by a large number of experiments and projects in a variety of application domains, including high energy physics, astrophysics and space science, medical physics and radiation protection. Its functionality and modeling capabilities continue to be extended, while its performance is enhanced. An overview of recent developments in diverse areas of the toolkit is presented. These include performance optimization for complex setups; improvements for the propagation in fields; new options for event biasing; and additions and improvements in geometry, physics processes and interactive ...


Adaptive Checkpointing For Master-Worker Style Parallelism (Extended Abstract), Gene D. Cooperman, Jason Ansel, Xiaoqin Ma 2010 Northeastern University

Adaptive Checkpointing For Master-Worker Style Parallelism (Extended Abstract), Gene D. Cooperman, Jason Ansel, Xiaoqin Ma

Gene D. Cooperman

No abstract provided.


Dmtcp: Transparent Checkpointing For Cluster Computations And The Desktop, Jason Ansel, Kapil Arya, Gene D. Cooperman 2010 Massachusetts Institute of Technology

Dmtcp: Transparent Checkpointing For Cluster Computations And The Desktop, Jason Ansel, Kapil Arya, Gene D. Cooperman

Gene D. Cooperman

DMTCP (Distributed MultiThreaded CheckPointing) is a transparent user-level checkpointing package for distributed applications. Checkpointing and restart is demonstrated for a wide range of over 20 well known applications, including MATLAB, Python, TightVNC, MPICH2, OpenMPI, and runCMS. RunCMS runs as a 680 MB image in memory that includes 540 dynamic libraries, and is used for the CMS experiment of the Large Hadron Collider at CERN. DMTCP transparently checkpoints general cluster computations consisting of many nodes, processes, and threads; as well as typical desktop applications. On 128 distributed cores (32 nodes), checkpoint and restart times are typically 2 seconds, with negligible run-time ...


End Of Year Report : Fy 2004, Gene Cooperman 2010 Northeastern University

End Of Year Report : Fy 2004, Gene Cooperman

Gene D. Cooperman

No abstract provided.


Notes On The Schur Complement, Jean H. Gallier 2010 University of Pennsylvania

Notes On The Schur Complement, Jean H. Gallier

Departmental Papers (CIS)

No abstract provided.


Test-Driven Web Application Development: Increasing The Quality Of Web Development By Providing Framework With An Emphasis On Test-Driven Design And Development Methodologies, Jason Hall 2010 Regis University

Test-Driven Web Application Development: Increasing The Quality Of Web Development By Providing Framework With An Emphasis On Test-Driven Design And Development Methodologies, Jason Hall

All Regis University Theses

Web applications , especially those based on interpreted programming languages , are quickly becoming more utilized and more commonplace than traditional client applications. Despite this growth, no open solution has yet fulfilled the need of a risk-reducing development framework that supports test-driven methodologies and tools designed to coordinate the resources responsible for the most effective development of web applications based on interpreted programming languages. This research paper presents a test-driven development framework consisting of openly available components that can be used by development teams writing web applications based on interpreted programming languages based on the methodologies and tools used by traditional software ...


Late 20th Century Hydrologic Change In Western North America: Regional Impacts And The Role Of Climate, Shaleen Jain 2010 Principal Investigator; University of Maine, Orono

Late 20th Century Hydrologic Change In Western North America: Regional Impacts And The Role Of Climate, Shaleen Jain

University of Maine Office of Research Administration: Grant Reports

Hydroclimatic variations and change directly impact the freshwater supplies in western North America. Streamflow in this region has shown increased variability of annual flow volumes and increasing synchroneity in the largest basins in the west towards the end of last century. As land-use change seems to play a lesser role, the PI will study the sensitivity of the western North American winter precipitation and related streamflow to El Nino-Southern Oscillation variations. The PI will use observations and multi-model ensemble integrations to study the decadal variations. The broader impact of this project will be an increase of the scientific knowledge required ...


Asynchronous Database Drivers, Michael Adam Heath 2010 Brigham Young University - Provo

Asynchronous Database Drivers, Michael Adam Heath

All Theses and Dissertations

Existing database drivers use blocking socket I/O to exchange data with relational database management systems (RDBMS). To concurrently send multiple requests to a RDBMS with blocking database drivers, a separate thread must be used for each request. This approach has been used successfully for many years. However, we propose that using non-blocking socket I/O is faster and scales better under load. In this paper we introduce the Asynchronous Database Connectivity in Java (ADBCJ) framework. ADBCJ provides a common API for asynchronous RDBMS interaction. Various implementations of the ADBCJ API are used to show how utilizing non-blocking socket I ...


First Order Analysis Of Nitrate Loading In The Upper Elbe River Basin, Czech Republic, Daniel J. Ritter 2010 Brigham Young University - Provo

First Order Analysis Of Nitrate Loading In The Upper Elbe River Basin, Czech Republic, Daniel J. Ritter

All Theses and Dissertations

Nitrate contamination of water is a worldwide issue. Nitrate is especially dangerous for young children, and may result in potentially fatal blue baby syndrome when concentration in drinking water is > 10 mg/L N-NO3. Nitrate in surface water may also lead to eutrophication. Sources of NO3- contamination include nitrate fertilizers, wastewater treatment plants, individual domestic septic systems, runoff from animal feedlots, and natural soil nitrogen. Nitrate contamination in the Elbe River drainage, covering 148,270 km2 in Germany and the Czech Republic, has been a long-term issue. This study examines the upper one-third of the basin, located almost entirely in ...


Tunable Optical Delay In Doppler-Broadened Cesium Vapor, Monte D. Anderson 2010 Air Force Institute of Technology

Tunable Optical Delay In Doppler-Broadened Cesium Vapor, Monte D. Anderson

Theses and Dissertations

Variable-delay tunable optical delay line or optical buffers are critical for the development of all-optical networks components as well as interferometry and analytic instruments. Recent research on slow light may hold the key for the development of the first practical tunable optical delay device. In this research the linear dispersion delay effects in an alkali vapor. The hyperfine relaxation observations present insight into the complex bleach wave dynamics during a high-intensity pulsed pump in DPAL systems.


Scattering Matrix Elements For The Nonadiabatic Collision B (2PJₐ) + H2 (1Σ+G, Ν, Ј) ↔ B (2PJ’ₐ) + H2 (1Σ+G, Ν’, J’)., Luke A. Barger 2010 Air Force Institute of Technology

Scattering Matrix Elements For The Nonadiabatic Collision B (2PJₐ) + H2 (1Σ+G, Ν, Ј) ↔ B (2PJ’ₐ) + H2 (1Σ+G, Ν’, J’)., Luke A. Barger

Theses and Dissertations

Scattering matrix elements are calculated for the nonadiabatic inelastic collision B (2Pj) + H2 (1Σ+g, ν, ј) ↔ B (2Pj’) + H2 (1Σ+g, ν’, j’). This calculation utilizes the effective potential energy surfaces for this collision generated by Garvin along with a correction to the asymptotic H2 potential. Wavepackets are propagated on these surfaces using a split-operator propagator. This propagation yields correlation functions between reactant and product Møller states which are used to calculate the scattering matrix elements with the channel packet method. These scattering matrix elements represent probability amplitudes ...


Gene Network Inference And Expression Prediction Using Recurrent Neural Networks And Evolutionary Algorithms, Heather Y. Chan 2010 Brigham Young University - Provo

Gene Network Inference And Expression Prediction Using Recurrent Neural Networks And Evolutionary Algorithms, Heather Y. Chan

All Theses and Dissertations

We demonstrate the success of recurrent neural networks in gene network inference and expression prediction using a hybrid of particle swarm optimization and differential evolution to overcome the classic obstacle of local minima in training recurrent neural networks. We also provide an improved validation framework for the evaluation of genetic network modeling systems that will result in better generalization and long-term prediction capability. Success in the modeling of gene regulation and prediction of gene expression will lead to more rapid discovery and development of therapeutic medicine, earlier diagnosis and treatment of adverse conditions, and vast advancements in life science research.


Factors Influencing Macroinvertebrate Diversity And Community Composition In Riverine Freshwater Rock Pools, Chtaura Jackson 2010 Virginia Commonwealth University

Factors Influencing Macroinvertebrate Diversity And Community Composition In Riverine Freshwater Rock Pools, Chtaura Jackson

Theses and Dissertations

I examined a system of 378-riverine rock pools situated along the James River in Richmond, Virginia, to uncover the factors influencing their macroinvertebrate diversity and community composition. I characterized (total = 60) the physical characteristics, water quality, hydrology, and community assemblages in July 2009 for a subset of pools. I examined whether selected environmental factors (pH, nearest neighbor distance, depth, surface area and inundation height) were related to macroinvertebrate diversity and community composition. Species richness and total abundance of all taxa increased with pool pH and surface area. Ordination indicates that nearest neighbor distance (NND) and pH varied significantly among pools ...


Graphs Of Bounded Degree And The P-Harmonic Boundary, Michael J. Puls 2010 CUNY John Jay College

Graphs Of Bounded Degree And The P-Harmonic Boundary, Michael J. Puls

Publications and Research

Let p be a real number greater than one and let G be a connected graph of bounded degree. We introduce the p-harmonic boundary of G and use it to characterize the graphs G for which the constant functions are the only p-harmonic functions on G. We show that any continuous function on the p-harmonic boundary of G can be extended to a function that is p-harmonic on G. We also give some properties of this boundary that are preserved under rough-isometries. Now let Gamma be a finitely generated group. As an application of our results, we characterize the vanishing ...


In Situ Observation Of Antisite Defect Formation During Crystal Growth, Matthew J. Kramer, Mikhail I. Mendelev, Ralph E. Napolitano 2010 Iowa State University

In Situ Observation Of Antisite Defect Formation During Crystal Growth, Matthew J. Kramer, Mikhail I. Mendelev, Ralph E. Napolitano

Materials Science and Engineering Publications

In situ x-ray diffraction (XRD) coupled with molecular dynamics (MD) simulations have been used to quantify antisite defect trapping during crystallization. Rietveld refinement of the XRD data revealed a marked lattice distortion which involves an a axis expansion and a c axis contraction of the stable C11b phase. The observed lattice response is proportional in magnitude to the growth rate, suggesting that the behavior is associated with the kinetic trapping of lattice defects. MD simulations demonstrate that this lattice response is due to incorporation of 1% to 2% antisite defects during growth.


Digital Commons powered by bepress