Chris Johnson

SciDAC Visualization and Analytics Center for Enabling Technologies (2008)

Bethel, E. Wes, Johnson, Chris, Joy, Ken, Ahern, Sean, Pascucci, Valerio, Childs, Hank, ...

The Visualization and Analytics Center for Enabling Technologies (VACET) focuses on leveraging scientific visualization and analytics software technology as an enabling technology for increasing...

DOE's SciDAC Visualization and Analytics Center for Enabling Technologies -- Strategy for Petascale Visual Data Analysis Success (2008)

Bethel, E. Wes, Johnson, Chris, Aragon, Cecilia, Prabhat, ???, Rubel, Oliver, Weber, Gunther, ...

The focus of this article is on how one group of researchers the DOE SciDAC Visualization and Analytics Center for Enabling Technologies (VACET) is tackling the daunting task of enabling knowledge...

VACET: Proposed SciDAC2 Visualization and Analytics Center for Enabling Technologies (2008)

Bethel, W., Johnson, Chris, Hansen, Charles, Parker, Steve, Sanderson, Allen, Silva, Claudio, ...

This paper accompanies a poster that is being presented at the SciDAC 2006 meeting in Denver, CO. This project focuses on leveraging scientific visualization and analytics software technology as an...

The effects of anxiety upon attention allocation to affective stimuli (2007)

Waters, Allison Maree, Nitz, Ashley B., Craske, Michelle G., Johnson, Chris

Pictures of emotionally aversive, neutral, and pleasant scenes were presented for 500 ms, followed by a probe presented in the same location (valid trials) or an alternate location (invalid trials)...

The effects of anxiety upon attention allocation to affective stimuli (2007)

Waters, Allison Maree, Nitz, Ashley B., Craske, Michelle G., Johnson, Chris

Pictures of emotionally aversive, neutral, and pleasant scenes were presented for 500 ms, followed by a probe presented in the same location (valid trials) or an alternate location (invalid trials)...

SciDAC Visualization and Analytics Center for Enabling Technology (2006)

Bethel, E. Wes, Johnson, Chris, Joy, Ken, Ahern, Sean, Pascucci, Valerio, Childs, Hank, ...

The SciDAC2 Visualization and Analytics Center for Enabling Technologies (VACET) began operation on 10/1/2006. This document, dated 11/27/2006, is the first version of the VACET project management...

Circum-Mediterranean cultural heritage and medicinal plant uses in traditional animal healthcare: a field survey in eight selected areas within the RUBIA project (2006)

Pieroni, Andrea, Giusti, Maria, De Pasquale, Caterina, Lenzarini, Cinzia, Censorii, Eleonora, Gonzáles-Tejero, María, ...

Abstract During the years 2003–2005, a comparative ethnobotanical field survey was conducted on remedies used in traditional animal healthcare in eight Mediterranean areas. The study sites were...

Demography in relation to population density in two herbivorous marsupials: Testing for source-sink dynamics versus independent regulation of population size. (2005)

Johnson, Chris, Vernes, Karl, Payne, Alison

We compared demography along gradients of population density in two medium-sized herbivorous marsupials, the common brushtail possum Trichosurus vulpecula and the rufous bettong Aepyprymnus...

Terminal reproductive investment in a marsupial (2005)

Johnson, Chris, Isaac, Joanne

Life history theory predicts that as organisms approach the end of their lifespan they should increase their reproductive effort (RE). In mammals, reproduction involves large transfers of energy from...

Demography in relation to population density in two herbivorous marsupials: Testing for source-sink dynamics versus independent regulation of population size. (2005)

Johnson, Chris, Vernes, Karl, Payne, Alison

We compared demography along gradients of population density in two medium-sized herbivorous marsupials, the common brushtail possum Trichosurus vulpecula and the rufous bettong Aepyprymnus...

Terminal reproductive investment in a marsupial (2005)

Johnson, Chris, Isaac, Joanne

Life history theory predicts that as organisms approach the end of their lifespan they should increase their reproductive effort (RE). In mammals, reproduction involves large transfers of energy from...

Aglets: a good idea for Spidering ? (2004)

Nick Craswell, Jason Haines, Brendan Humphreys, Chris Johnson, Paul Thistlewaite

Introduction Many individuals and businesses now rely on the Web for promulgating and finding information, and in particular, rely on centralised search databases. The extent to which these databases...

Statistical Analysis For FEM (2004)

Leonid Zhukov, David Weinstein, Chris Johnson

Estimating the location and distribution of electric current sources within the brain from electroencephalographic (EEG) recordings is an ill-posed inverse problem. The ill-posed nature of the...

Volume Currents in Forward and Inverse Magnetoencephalographic (2004)

Robert Van Uitert, David Weinstein, Chris Johnson

Volume currents are important for the accurate calculation of magnetoencephalographic #MEG# forward or inverse simulations in realistic head models. We verify the accuracy of our finite element...

The Role of Night Vision Equipment in Military Incidents and Accidents (2004)

Chris Johnson

Night vision devices provide enormous benefits. They enable personnel to carry out operations under conditions that would not otherwise be possible. However, these benefits carry considerable risks....

Powerpoint to the People": Suiting the Word to the Audience (2004)

Ren Hexel, Chris Johnson, Bob Kummerfeld, Aaron Quigley

A computerised system supporting public presentations that are "personalised" at two levels is now possible. Firstly, the system exploits context information to adapt the large-screen projected...

Lead Field Basis for FEM (2003)

David Weinstein, Leonid Zhukov, Chris Johnson

In recent years, significant progress has been made in the area of EEG/MEG source imaging. Source imaging on simple spherical models has become increasingly e#cient, with consistently reported...

Lead Field Basis for FEM (2003)

David Weinstein, Leonid Zhukov, Chris Johnson

In recent years, significant progress has been made in the area of EEG/MEG source imaging. Source imaging on simple spherical models has become increasingly e#cient, with consistently reported...

Independent Component Analysis For EEG Source (2003)

Leonid Zhukov, David Weinstein, Chris Johnson

A pervasive problem in neuroscience is determining which regions of the brain are active, given voltage measurements at the scalp. If accurate solutions to such problems could be obtained,...

The Team-Based Operation of Safety-Critical (2003)

Chris Johnson

This paper analyzes a range of incidents involving team-based interaction with safety-critical programmable systems. The incidents were submitted to NASA's Aviation Safety Reporting System (ASRS) and...

Using IEC 61508 to Guide the Investigation of Computer-Related Incidents and Accidents (2003)

Chris Johnson

Relatively few investigation techniques have been specifically developed to identify the causal factors that contribute to mishaps involving safety-critical computer systems. This is a significant...

Volume Currents in Forward and Inverse MEG Simulations using Realistic (2002)

Robert Van Uitert, David Weinstein, Chris Johnson

Many magnetoencephalography (MEG) forward and inverse simulation models employ spheres, a singular shape which does not require consideration of volume currents. With more realistic, inhomogeneous,...

Spectral Characteristics of the Global Moisture Distribution and Their Importance in Objective Analysis of Moisture for NWP Models, (2002)

Norquist,Donald C., Johnson,Chris

Using data sets of observations of atmospheric variables on a global scale, the spectral distribution of atmospheric moisture is compared with that of wind and mass fields. Results show that,...

Computational Field Visualization (2001)

Chris Johnson, Dean Brederson, Chuck Hansen, Milan Ikits, Gordon Kindlmann, Yarden Livnat, ...

Introduction Today, scientists, engineers, and medical researchers routinely use computers to simulate complex physical phenomena. Such simulations present new challenges for computational...

A Framework For Computational Anatomy (2001)

Chris Johnson, Paul M. Thompson, Arthur W. Toga

The rapid collection of brain images from healthy and diseased subjects has stimulated the development of powerful mathematical algorithms to compare, pool and average brain data across whole...

Spatio-temporal Multi-dipole Source Localization Using ICA and Lead-Fields in FEM Head Models (2001)

Leonid Zhukov, David Weinstein, Chris Johnson, Rob Macleod

| In this paper we introduce a framework for the solution of the multi-dipole, time-dependent, source localization problem in realistic head models. Our technique combines a PCA/ICA signal...

The Uintah Parallelism Infrastructure: A Performance Evaluation on the SGI Origin 2000 (2001)

John Mccorquodale, J. Davison, St. Germain, Steven G. Parker, Chris Johnson

Uintah is a component-based visual problem solving environment (PSE) designed to specifically address the unique problems inherent in running massively parallel scientific computations on terascale...

Aglets: a good idea for Spidering ? (2001)

Nick Craswell, Jason Haines, Brendan Humphreys, Chris Johnson, Paul Thistlewaite

Introduction Many individuals and businesses now rely on the Web for promulgating and finding information, and in particular, rely on centralised search databases. The extent to which these databases...

Signals Passed at Danger: A Case Study in the Application of Visualisation Techniques (2001)

Fraser Speirs, Chris Johnson, G Qq

This paper presents the reporting of Signals Passed at Danger (SPAD) - the term used to describe an incident when a train passes a signal displaying a danger aspect without authorisation. This...

Lead-field Bases for Electroencephalography Source Imaging (2001)

David Weinstein, Leonid Zhukov, Chris Johnson

In recent years, signicant progress has been made in the area of electroencephalography (EEG) source imaging. Source localization on simple spherical models has become increasingly ecient, with...

Lead- eld Bases for Electroencephalography Source Imaging (2001)

David Weinstein, Leonid Zhukov, Chris Johnson

In recent years, signicant progress has been made in the area of electroencephalography (EEG) source imaging. Source localization on simple spherical models has become increasingly ecient, with...

Adjustment of offspring sex ratios in relation to availability of resources for philopatric offspring in the common brushtail possum (2001)

Johnson, Chris

The Local Resource Competition (LRC) hypothesis predicts that where philopatric offspring compete for resources with their mothers, offspring sex ratios will be biased in favour of the dispersing...

Adjustment of offspring sex ratios in relation to availability of resources for philopatric offspring in the common brushtail possum (2001)

Johnson, Chris

The Local Resource Competition (LRC) hypothesis predicts that where philopatric offspring compete for resources with their mothers, offspring sex ratios will be biased in favour of the dispersing...

Performance Impact Of The Elimination Of Direct Labor Variance Reporting: A Field Study 1. (2000)

Rajiv D. Banker, Sarvanan Devaraj, Roger G. Schroeder, Kingshuk K. Sinha, Chris Johnson, Debbie Larson, ...

this paper is to empirically test these theoretical predictions about the performance impact of eliminating direct labor variance reporting. We analyze performance data from 7 plants ("experimental...

A Spatio-Temporal Object Model and Query Language (2000)

Bo Huang, Michael F. Worboys, Chris Johnson, John Stell, Keith Mason

this paper concerns the spatio-temporal data model and an associated query language.

Physically-Based B-Spline Surface Sculpting (2000)

Colette J. Mullenhoff, Chris Johnson, Peter Shirley

Conventional B-spline modeling software offers the designer shape interaction and manipulation through editing the associated control points, orders, and knot vector parameters. Such modeling is...

Independent Component Analysis For EEG Source Localization In Realistic Head Models (1999)

Leonid Zhukov, David Weinstein, Chris Johnson

A pervasive problem in neuroscience is determining which regions of the brain are active, given voltage measurements at the scalp. If accurate solutions to such problems could be obtained,...

Independent Component Analysis For EEG Source Localization In Realistic Head Models (1999)

Leonid Zhukov, David Weinstein, Chris Johnson

A pervasive problem in neuroscience is determining which regions of the brain are active, given voltage measurements at the scalp. If accurate solutions to such problems could be obtained,...

Aglets: a good idea for Spidering? (1999)

Nick Craswell, Jason Haines, Brendan Humphreys, Chris Johnson, Paul Thistlewaite

Introduction Many individuals and businesses now rely on the Web for promulgating and finding information, and in particular, rely on centralised search databases. The extent to which these databases...

Keele, England, July 20--29, 1993 (1999)

Richard Bornat, The Dov Gabbay, Wilfrid Hodges, Martin Hyl, Thomas Jech, David Makinson, ...

Natural Deduction the well-known connections between Proof Theory and Category Theory. More precisely, we shall show how to systematically associate to any operator #, whose introduction and...

Intuitive Policy Specification for Optimized Flow of Asynchronous C3I Transmission in Operations (IPSO FACTO) (1998)

Richardson, Jim, Miller, Chris, Johnson, Chris, Shackleton, John, Funk, Harry

We address the problem of allocating scarce communications resources in a military wide area network so that the information flows best support mission objectives. IPSO FACTO enables commanders to...

Pre-fetching tree-structured data in distributed memory (1998)

Weaver, Lex, Johnson, Chris

A distributed heap storage manager has been implemented on the Fujitsu AP1000 multicomputer. The performance of various pre-fetching strategies is experimentally compared. Subjective programming...

An Efficient Implementation of the Message Passing Interface (MPI) on the Fujitsu AP1000 (1997)

David Sitsky, David Walsh, Chris Johnson

The message passing interface standard released in April 1994 by the MPI Forum [2], defines a set of message passing primitives for multicomputers and clustered systems. The standard provides a large...

Implementation and Performance of the MPI Message Passing Interface on the Fujitsu AP1000 Multicomputer (1997)

David Sitsky, David Walsh, Chris Johnson

MPI is the new standard which defines a set of message passing operations for multicomputers and clustered systems. In comparison to other popular message passing systems, MPI provides a richer...

HeROD Flavoured Oct-Trees: Scientific Computation with a Multicomputer Persistent Object Store (1997)

Stephen Fenwick, Chris Johnson

Using a persistent multicomputer object store should greatly simplify the writing of distributed memory parallel programs operating on irregular, object-structured data, by removing from the...

HeROD flavoured oct-trees: scientific computation with a multicomputer persistent object store (1997)

Fenwick, Stephen, Johnson, Chris

Using a persistent multicomputer object store should greatly simplify the writing of distributed memory parallel programs operating on irregular, object-structured data, by removing from the...

HeROD flavoured oct-trees: scientific computation with a multicomputer persistent object store (1997)

Fenwick, Stephen, Johnson, Chris

Using a persistent multicomputer object store should greatly simplify the writing of distributed memory parallel programs operating on irregular, object-structured data, by removing from the...

HeROD flavoured oct-trees: scientific computation with a multicomputer persistent object store (1997)

Fenwick, Stephen, Johnson, Chris

Using a persistent multicomputer object store should greatly simplify the writing of distributed memory parallel programs operating on irregular, object-structured data, by removing from the...

HeROD flavoured oct-trees: scientific computation with a multicomputer persistent object store (1997)

Fenwick, Stephen, Johnson, Chris

Using a persistent multicomputer object store should greatly simplify the writing of distributed memory parallel programs operating on irregular, object-structured data, by removing from the...

Pre-Fetching Tree-Structured Data in Distributed Memory (1996)

Lex Weaver, Chris Johnson

A distributed heap storage manager has been implemented on the Fujitsu AP1000 multicomputer. The performance of various pre-fetching strategies is experimentally compared. Subjective programming...

Pre-Fetching Tree-Structured Data in Distributed Memory (1996)

Lex Weaver, Chris Johnson

A distributed heap storage manager has been implemented on the Fujitsu AP1000 multicomputer. The performance of various pre-fetching strategies is experimentally compared. Subjective programming...

An Efficient Implementation of the Message Passing Interface (MPI) on the Fujitsu AP1000 (1994)

David Sitsky, David Walsh, Chris Johnson

The message passing interface standard released in April 1994 by the MPI Forum [2], defines a set of message passing primitives for multicomputers and clustered systems. The standard provides a large...

Implementation and Performance of the MPI Message Passing Interface on the Fujitsu AP1000 Multicomputer (1994)

David Sitsky, David Walsh, Chris Johnson

MPI is the new standard which defines a set of message passing operations for multicomputers and clustered systems. In comparison to other popular message passing systems, MPI provides a richer...

The Formal Analysis Of Human-Computer Interaction During Accident Investigations (1994)

Chris Johnson

This paper presents ways in which formal methods can be exploited to address these problems. Mathematical notations provide means of representing and reasoning about the circumstances that lead to...

The role of literate computing in undergraduate curricula (1994)

Bossomaier, Terry, Johnson, Chris

Teaching medium scale program design to second-year computer science students is highly desirable, but difficult to incorporate within an already fully-loaded course structure. An intermediate...

The role of literate computing in undergraduate curricula (1994)

Bossomaier, Terry, Johnson, Chris

Teaching medium scale program design to second-year computer science students is highly desirable, but difficult to incorporate within an already fully-loaded course structure. An intermediate...

The role of literate computing in undergraduate curricula (1994)

Bossomaier, Terry, Johnson, Chris

Teaching medium scale program design to second-year computer science students is highly desirable, but difficult to incorporate within an already fully-loaded course structure. An intermediate...

The role of literate computing in undergraduate curricula (1994)

Bossomaier, Terry, Johnson, Chris

Teaching medium scale program design to second-year computer science students is highly desirable, but difficult to incorporate within an already fully-loaded course structure. An intermediate...

Appropriate use of computing technology (1992)

Johnson, Chris

1. As the computing boom gets quieter... 2. What benefit is a publicly open system? 3. What harm is in computerised systems? 4. So - what is appropriate in computing? Appropriate computing or...

Appropriate use of computing technology (1992)

Johnson, Chris

1. As the computing boom gets quieter...2. What benefit is a publicly open system?3. What harm is in computerised systems?4. So - what is appropriate in computing?Appropriate computing or computing...

Appropriate use of computing technology (1992)

Johnson, Chris

1. As the computing boom gets quieter... 2. What benefit is a publicly open system? 3. What harm is in computerised systems? 4. So - what is appropriate in computing? Appropriate computing or...

Appropriate use of computing technology (1992)

Johnson, Chris

1. As the computing boom gets quieter... 2. What benefit is a publicly open system? 3. What harm is in computerised systems? 4. So - what is appropriate in computing? Appropriate computing or...

Appropriate use of computing technology (1992)

Johnson, Chris

1. As the computing boom gets quieter... 2. What benefit is a publicly open system? 3. What harm is in computerised systems? 4. So - what is appropriate in computing? Appropriate computing or...

Lead Field Basis for FEM Source Localization (1970)

David Weinstein, Leonid Zhukov, Chris Johnson

In recent years, significant progress has been made in the area of EEG/MEG source imaging. Source imaging on simple spherical models has become increasingly e#cient, with consistently reported...

Circum-Mediterranean cultural heritage and medicinal plant uses in traditional animal healthcare: a field survey in eight selected areas within the RUBIA project

Pieroni, Andrea, Giusti, Maria Elena, De Pasquale, Caterina, Lenzarini, Cinzia, Censorii, Eleonora, Gonzáles-Tejero, María Reyes, ...

During the years 2003–2005, a comparative ethnobotanical field survey was conducted on remedies used in traditional animal healthcare in eight Mediterranean areas. The study sites were selected...

Circum-Mediterranean cultural heritage and medicinal plant uses in traditional animal healthcare: a field survey in eight selected areas within the RUBIA project

Pieroni, Andrea, Giusti, Maria Elena, De Pasquale, Caterina, Lenzarini, Cinzia, Censorii, Eleonora, Gonzáles-Tejero, María Reyes, ...

During the years 2003–2005, a comparative ethnobotanical field survey was conducted on remedies used in traditional animal healthcare in eight Mediterranean areas. The study sites were selected...

Time to stop sniffing the air: snapshot survey

Johnson, Chris, Goodman, Neville W

Objective To determine whether the phrase “sniffing the morning air” is useful in positioning patients for tracheal intubation.