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

Physical Sciences and Mathematics Commons

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

262,119 Full-Text Articles 330,953 Authors 78,898,844 Downloads 442 Institutions

All Articles in Physical Sciences and Mathematics

Faceted Search

262,119 full-text articles. Page 8464 of 8465.

Estimation Of The Area Of Sealed Soil Using Gis Technology And Remote Sensing, Stanisław Białousz, Przemysław Kupidura 2009 Warsaw University of Technology

Estimation Of The Area Of Sealed Soil Using Gis Technology And Remote Sensing, Stanisław Białousz, Przemysław Kupidura

Przemysław Kupidura

Soil sealing can be defined as the destruction or covering of soil by buildings, constructions and artificial layers completely or partly impermeable (asphalt, concrete, etc.) It is the most intense form of land consumption and is essentially an irreversible process. Soil is sealed when agricultural or other biologically land is taken into the built environment. It is also a continuing process within existing urban areas, especially where urban population and the density of built structures is increasing and residual inner-city green zones are reduced. The paper concerns the methodology for an estimation of the area of sealed soil using GIS …


High Performance Computing Instrumentation And Research Productivity In U.S. Universities, Linh B. Ngo, Amy W. Apon, Stanley Ahalt, Vijay Dantuluri, Constantin Gurdgiev, Moez Limayem, Michael Stealey 2009 Clemson University

High Performance Computing Instrumentation And Research Productivity In U.S. Universities, Linh B. Ngo, Amy W. Apon, Stanley Ahalt, Vijay Dantuluri, Constantin Gurdgiev, Moez Limayem, Michael Stealey

Linh B Ngo

This paper studies the relationship between investments in High-Performance Computing (HPC) instrumentation and research competitiveness. Measures of institutional HPC investment are computed from data that is readily available from the Top 500 list, a list that has been published twice a year since 1993 that lists the fastest 500 computers in the world at that time. Institutions that are studied include US doctoral-granting institutions that fall into the very high or high research rankings according to the Carnegie Foundation classifications and additional institutions that have had entries in the Top 500 list. Research competitiveness is derived from federal funding data, …


Forward Modeling Synsedimentary Deformation Associated With A Prograding Steep-Sloped Carbonate Margin, Phillip G. Resor 2009 Wesleyan University

Forward Modeling Synsedimentary Deformation Associated With A Prograding Steep-Sloped Carbonate Margin, Phillip G. Resor

Phillip G Resor

Differential compaction associated with prograding and aggrading steep-rimmed carbonate margins leads to penecontemporaneous and post- depositional modifications of stratal geometries and tensile and shear stress concentrations that result in brittle deformation. In an effort to investigate controls on these deformation processes, we employ a step-wise gravity loaded elastic model that captures pre-failure displacement and stress field patterns for a depositional geometry based on the Permian Capitan depositional system, Guadalupe Mountains, West Texas and New Mexico, USA. We consider four model geometries with varying progradation to aggradation (P/A) ratio, from strongly prograding (P/A=10) to strongly aggrading (P/A=0.1). The strongly prograding case …


Bayesian Inference For A Periodic Stochastic Volatility Model Of Intraday Electricity Prices, Michael S. Smith 2009 Melbourne Business School

Bayesian Inference For A Periodic Stochastic Volatility Model Of Intraday Electricity Prices, Michael S. Smith

Michael Stanley Smith

The Gaussian stochastic volatility model is extended to allow for periodic autoregressions (PAR) in both the level and log-volatility process. Each PAR is represented as a first order vector autoregression for a longitudinal vector of length equal to the period. The periodic stochastic volatility model is therefore expressed as a multivariate stochastic volatility model. Bayesian posterior inference is computed using a Markov chain Monte Carlo scheme for the multivariate representation. A circular prior that exploits the periodicity is suggested for the log-variance of the log-volatilities. The approach is applied to estimate a periodic stochastic volatility model for half-hourly electricity prices …


Bayesian Skew Selection For Multivariate Models, Michael S. Smith, Anastasios Panagiotelis 2009 Melbourne Business School

Bayesian Skew Selection For Multivariate Models, Michael S. Smith, Anastasios Panagiotelis

Michael Stanley Smith

We develop a Bayesian approach for the selection of skew in multivariate skew t distributions constructed through hidden conditioning in the manners suggested by either Azzalini and Capitanio (2003) or Sahu, Dey and Branco~(2003). We show that the skew coefficients for each margin are the same for the standardized versions of both distributions. We introduce binary indicators to denote whether there is symmetry, or skew, in each dimension. We adopt a proper beta prior on each non-zero skew coefficient, and derive the corresponding prior on the skew parameters. In both distributions we show that as the degrees of freedom increases, …


The Tangled Tale Of Phase Space, David D. Nolte 2009 Purdue University

The Tangled Tale Of Phase Space, David D. Nolte

David D Nolte

(Preview of Chapter 6: Galileo Unbound: Oxford 2018) Phase space has been called one of the most powerful inventions of modern science.  But its historical origins are clouded in a tangle of independent discovery and mis-attributions that persist today.  This Physics Today article unravels the twisted tale of the discovery and the naming of phase space that began with Liouville in 1838, but by no means ended there, culminating in an encyclopedia article of 1911 that had unintended and lasting etymological side effects never intended by its authors.


Impact Of The Australia-Us Free Trade Agreement On Australian Medicines Regulation And Prices, Thomas A. Faunce, James Bai, Duy Nguyen 2009 Australian National University

Impact Of The Australia-Us Free Trade Agreement On Australian Medicines Regulation And Prices, Thomas A. Faunce, James Bai, Duy Nguyen

Thomas A Faunce

The Australia – United States Free Trade Agreement (AUSFTA) came into force on 1 January 2005. Before and subsequently to the AUSFTA being concluded, controversy surrounded the debate over its impact on Australia ’ s health policy, specifically on regulation of pharmaceutical patents and Australia ’ s cost-effectiveness system relating to prescription medicine prices known as the Pharmaceutical Benefits Scheme (PBS). This article examines the expectations of both parties in the pharmaceutical sector with regard to the AUSFTA, as well as how successfully they were achieved. It seeks to analyse important relevant outcomes for regulators, the public and pharmaceutical industry, …


Nanotechnology And The International Law Of Weaponry: Towards International Regulation Of Nano-Weapons., Thomas A. Faunce, Hitoshi Nasu 2009 Australian National University

Nanotechnology And The International Law Of Weaponry: Towards International Regulation Of Nano-Weapons., Thomas A. Faunce, Hitoshi Nasu

Thomas A Faunce

The development of nanotechnology for military application is an emerging area of research and development, the pace and extent of which has not been fully anticipated by international legal regulation. Nano-weapons are referred to here as objects and devices using nanotechnology or causing effects in nano-scale that are designed or used for harming humans. Such weapons, despite their controversial human and environmental toxicity, are not comprehensively covered by specific, targeted regulation under international law. This article critically examines current international humanitarian law and arms control law regimes to determine whether significant gaps exist in the regulation of nanotechnology focused on …


Pricing Residential Water To Account For Scarcity In Cyprus, Theodoros Zachariadis 2009 Cyprus University of Technology

Pricing Residential Water To Account For Scarcity In Cyprus, Theodoros Zachariadis

Theodoros Zachariadis

No abstract provided.


Effect Of Spontaneous Gas Expansion And Mobilization On The Aqueous-Phase Concentrations Above A Dense Non-Aqueous Phase Liquid Pool., Kevin G. Mumford, James Smith, Sarah E. Dickson 2009 Queen's University - Kingston, Ontario

Effect Of Spontaneous Gas Expansion And Mobilization On The Aqueous-Phase Concentrations Above A Dense Non-Aqueous Phase Liquid Pool., Kevin G. Mumford, James Smith, Sarah E. Dickson

Sarah E Dickson

This paper presents a framework to quantify the overall variability of the model estimations of Total Polychlorinated Biphenyls (Total PCBs) concentrations in the Niagara River on the basis of the uncertainty of few model parameters and the natural variability embedded in some of the model input variables. The results of the uncertainty analysis are used to understand the importance of stochastic model components and their effect on the overall reliability of the model output and to evaluate multiple sources of uncertainty that might need to be further studied. The uncertainty analysis is performed using a newly developed point estimate method, …


Interdependence Of In-Cell Xenon Density And Temperature During Rb/129xe Spin-Exchange Optical Pumping Using Vhg-Narrowed Laser Diode Arrays, Nicholas Whiting, Panayiotis Nikolaou, Neil A. Eschmann, Michael J. Barlow, Boyd M. Goodson 2009 Rowan University

Interdependence Of In-Cell Xenon Density And Temperature During Rb/129xe Spin-Exchange Optical Pumping Using Vhg-Narrowed Laser Diode Arrays, Nicholas Whiting, Panayiotis Nikolaou, Neil A. Eschmann, Michael J. Barlow, Boyd M. Goodson

Nicholas Whiting

The 129Xe nuclear spin polarization (PXe) that can be achieved via spin-exchange optical pumping (SEOP) is typically limited at high in-cell xenon densities ([Xe]cell), due primarily to corresponding reductions in the alkali metal electron spin polarization (e.g. PRb) caused by increased non-spin-conserving Rb–Xe collisions. While demonstrating the utility of volume holographic grating (VHG)-narrowed lasers for Rb/129Xe SEOP, we recently reported [P. Nikolaou et al., JMR 197 (2009) 249] an anomalous dependence of the observed PXe on the in-cell xenon partial pressure (pXe), wherein PXe values were abnormally low at decreased pXe, peaked at moderate pXe (~300 torr), and remained surprisingly …


Wind Energy Deployment: Global Lessons For West Michigan, Erik Edward Nordman 2009 Grand Valley State University

Wind Energy Deployment: Global Lessons For West Michigan, Erik Edward Nordman

Erik Edward Nordman

West Michigan Wind Assessment Issue Brief #1 This first of series of issue briefs summarizes the factors that have influenced wind energy deployment across the country and around the world. It also brings the lessons home to West Michigan's coastal zone.


Wind Power And Human Health: Flicker, Noise And Air Quality, Erik Edward Nordman 2009 Grand Valley State University

Wind Power And Human Health: Flicker, Noise And Air Quality, Erik Edward Nordman

Erik Edward Nordman

West Michigan Wind Assessment Issue Brief #2 The second of a series of wind energy issue briefs synthesizes the state of the science around wind energy siting issues like flicker and noise, and analyzes how West Michigan communities are addressing these challenges. The issue brief also assesses how wind energy could improve air quality and human health outcomes in West Michigan and the region.


Designing Digital Library Of Perso-Arabic Script: An Experiment., Nadim Akhtar Khan, Rosy Jan, Sheikh Shazia 2009 University of Kashmir

Designing Digital Library Of Perso-Arabic Script: An Experiment., Nadim Akhtar Khan, Rosy Jan, Sheikh Shazia

NADIM AKHTAR KHAN

The Greenstone digital library software is a comprehensive system for building and distributing digital library collections providing a new way for organizing and publishing information on the Internet. The paper describes how multilingual digital library collections can be created and customized using various features available in Greenstone Digital Library Software. It is an attempt towards creating and managing digital library collection in different scripts for M. Phil and Ph. D theses submitted to University of Kashmir in Arabic, Persian, Kashmiri and Urdu.


Knoor: Knowledge Repository Open Network., S M. Shafi, Nadim Akhtar Khan, Rosy Jan 2009 university of Kashmir, Srinagar, INDIA, 190006

Knoor: Knowledge Repository Open Network., S M. Shafi, Nadim Akhtar Khan, Rosy Jan

NADIM AKHTAR KHAN

The paper discusses KNoor (Knowledge Repository Open Network) which aims at harvesting and aggregating the scholarly products emanating from research and scientific institutions of Jammu & Kashmir. The paper highlights genesis, significance, cooperation and various modules of access etc with screen shots as a unique cooperative, multilingual repository of research papers, ETDs and conference proceedings of three premier institutes of valley (University of Kashmir, Sher-e-Kashmir Institute of Medical sciences, Sher-e-Kashmir University of Agricultural Sciences) in the first phase. It also discusses challenges and lessons learnt in the process with a view to help other institutions to advance the mission of …


New 2-Aminoethylimidazole-Based Dicarboxylic Acid Receptor Derived From Cholestane, Jyoti Ramesh Jadhav, Md Wasi Ahmad, Hong Seok Kim 2009 Kyungpook National University

New 2-Aminoethylimidazole-Based Dicarboxylic Acid Receptor Derived From Cholestane, Jyoti Ramesh Jadhav, Md Wasi Ahmad, Hong Seok Kim

Dr. Mohammad Wasi Ahmad (Md Wasi Ahmad)

A new facial amphiphile cholestane-based receptor 1 containing a 2-imidazolylethylamino moiety at the 3a and 7a positions of cholestane was synthesized. Recognition selectivity of the new receptor 1 with various dicarboxylic acids was assessed by 1H NMR titration. Maleic acid showed the highest binding constant among all the tested acids


On The Statistical Accuracy Of Biomarker Assays Of Hiv Incidence, Ron Brookmeyer 2009 University of California, Los Angeles

On The Statistical Accuracy Of Biomarker Assays Of Hiv Incidence, Ron Brookmeyer

Ron Brookmeyer

Objective: To evaluate the statistical accuracy of estimates of current HIV incidence rates from cross-sectional surveys, and to identify characteristics of assays that improve accuracy.

Methods: Performed mathematical and statistical analysis of the cross-sectional estimator of HIV incidence to evaluate bias and variance. Developed probability models to evaluate impact of long tails of the window period distribution on accuracy.

Results: The standard cross-sectional estimate of HIV incidence rate is estimating a time-lagged incidence where the lag time, called the shadow, depends on the mean and the coefficient of variation of window periods. Equations show how the shadow increases with the …


Investigating Urban Sprawl Using Remote Sensing And Gis Technology, Przemysław Kupidura 2009 Warsaw University of Technology

Investigating Urban Sprawl Using Remote Sensing And Gis Technology, Przemysław Kupidura

Przemysław Kupidura

The paper concerns the analysis of urban sprawl. The presented example of Lomianki – the municipality situated in the neighbourhood of Warsaw – capital city of Poland, shows dynamic changes of rural-urban fringe, called sub-urbanization. This kind of process is characterized by incoherence of spatial structure, disproportions between development of built-up areas and transport network, underdevelopment of service built-up areas and public spaces and mixing of urban and rural structures. Such a dynamic development leads also to an increasing of area of sealed (impermeable) zones, what is very important due to water economics. The multi-temporal dataset of aerial and satellite …


Using Twitter Hash Tags To Demonstrate Basic Concepts From Network Analysis, Matt Bogard 2009 Western Kentucky University

Using Twitter Hash Tags To Demonstrate Basic Concepts From Network Analysis, Matt Bogard

Matt Bogard

Social Network Analysis focuses on finding patterns in interactions between people or entities. These patterns may be described in the form of a network. Network analysis in general has many applications including models of student integration and persistence, business to business supply chains, terrorist cells, or analysis of social media such as Facebook and Twitter. This presentation provides a reference for basic concepts from social network analysis with examples using tweets from Twitter.


The Journey To Safety: Conflict-Driven Migration Flows In Colombia, Gianfranco Piras, Nancy Lozano-Gracia, Geoffrey Hewings, Ana Maria Ibanez 2009 Regional Research Institute, West Virginia University

The Journey To Safety: Conflict-Driven Migration Flows In Colombia, Gianfranco Piras, Nancy Lozano-Gracia, Geoffrey Hewings, Ana Maria Ibanez

Gianfranco Piras

No abstract provided.


Digital Commons powered by bepress