T. Fredian - Academia.edu (original) (raw)

Papers by T. Fredian

Research paper thumbnail of Disclaimer

This report was prepared as an account of work sponsored by an agency of the United States Govern... more This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

Research paper thumbnail of Abstract DRAFT COPY (to be published in Journal of Grid Computing) ROAM: An Authorization Manager for Grids

was created to provide a simple but flexible authorization system for the FusionGrid computationa... more was created to provide a simple but flexible authorization system for the FusionGrid computational grid. ROAM builds on and extends previous community efforts by both responding to access authorization requests and by providing a Web interface for resource management. ROAM works with the Globus Resource Allocation Manager (GRAM), and is general enough to be used by other virtual organizations that use Globus middleware or X.509/TLS authentication schemes to secure a grid of distributed resources. In addition to describing ROAM, this paper discusses the basic design parameters of a grid authorization system and the reasons for the choices made in the ROAM design. 1

Research paper thumbnail of Data acquisition system for Alcator

The Alcator C-Mod experiment requires an efficient data handling system to acquire and distribute... more The Alcator C-Mod experiment requires an efficient data handling system to acquire and distribute the large number of measurements recorded during each pulse of the tokamak. Over 2000 signals amounting to over 80 megabytes of data are stored and distributed to 40 workstations for display and analysis. With machine pulses occurring every 10 to 15 min, most of the information must be distributed within 2 to 3 min after the pulse to enable the experimentalist to adjust the control settings for the next pulse. In addition to the local control room data distribution requirements, the system must also provide data access to remote sites which monitor diagnostics installed on the Alcator C-Mod experiment. This article will describe the hardware and software used to accomplish data handling tasks. ©1997 American Institute of Physics. @S0034-6748 ~97!64801-7#

Research paper thumbnail of PFC / JA-96-21 Data Acquisition System for Alcator C-Mod

The Alcator C-Mod experiment requires an efficient data handling system to acquire and distribute... more The Alcator C-Mod experiment requires an efficient data handling system to acquire and distribute the large number of measurements recorded during each pulse of the tokamak. Over 2000 signals amounting to over 80 megabytes of data are stored and distributed to 40 workstations for display and analysis. With machine pulses occurring every ten to fifteen minutes, most of the information must be distributed within 2-3 minutes after the pulse to enable the experimentalist to adjust the control settings for the next pulse. In addition to the local control room data distribution requirements, the system must also provide data access to remote sites which monitor diagnostics installed on the Alcator C-Mod experiment. This paper will describe the hardware and software used to accomplish this data handling task.

Research paper thumbnail of Control and Data Acquisition System for Lower Hybrid Current Drive in Alcator C-Mod

AIP Conference Proceedings, 2003

A lower hybrid current drive (LHCD) system is being installed on the Alcator C-Mod tokamak. Initi... more A lower hybrid current drive (LHCD) system is being installed on the Alcator C-Mod tokamak. Initially, 12 klystrons operating at 4.6 GHz will deliver a total power of 3 MW to the coupler. The LHCD system will make it possible to modify the current density profile in the outer half of the plasma. This implies that the q-profile can be manipulated, thereby enabling the study of advanced tokamak regimes. In this paper we describe the overall structure of the control and data acquisition system for LHCD. The acquisition setup collects data from the active controller, the transmitter protection and the coupler protection systems. Long pulse tests of the klystrons are presented and a monitor camera is introduced.

Research paper thumbnail of Remote Participation of Large-Scale Fusion Experiments

This paper examines the past, present, and future remote operation of large-scale fusion experime... more This paper examines the past, present, and future remote operation of large-scale fusion experiments by large, geographically dispersed teams. The fusion community has considerable experience placing remote collaboration tools in the hands of real users. Tools to remotely view operations and control selected instrumentation and analysis tasks were in use as early as 1992 and full remote operation of an entire tokamak experiment was demonstrated in 1996. Today's experiments invariably involve a mix of local and remote researchers, with sessions routinely led from remote institutions. Currently, the National Fusion Collaboratory Project has created a FusionGrid for secure remote computations and has placed collaborative tools into operating control rooms. Looking towards the future, ITER will be the next major step in the international program. Fusion experiments put a premium on near real-time interactions with data and among members of the team and though ITER will generate more data than current experiments, the greatest challenge will be the provisioning of systems for analyzing, visualizing and assimilating data to support distributed decision making during ITER operation.

Research paper thumbnail of Lessons learned from the MIT Tara control and data system

The control and data system of the MIT Tara Tandem Mirror has worked successfully throughout the ... more The control and data system of the MIT Tara Tandem Mirror has worked successfully throughout the lifetime of the experiment (1983 through 1987). As the Tara project winds down, it is appropriate to summarize the lessons learned from the implementation and operation of the control and data system over the years and in its final form. The control system handled

Research paper thumbnail of SciDAC Fusiongrid Project--A National Collaboratory to Advance the Science of High Temperature Plasma Physics for Magnetic Fusion

Research paper thumbnail of A National Collaboratory to Advance the Science of High Temperature Plasma Physics for Magnetic Fusion

Research paper thumbnail of MDS-PIUS: A Software System for Fast Control and Data Acquisition in Fusion Experiments

Seventh Conference Real Time '91 on Computer Applications in Nuclear, Particle and Plasma Physics Conference Record

ABSTRACT

Research paper thumbnail of Graphical user interface of RFX control and data acquisition system

15th IEEE/NPSS Symposium. Fusion Engineering

Type of signals slow digital inpudoutputs fast digital inpudoutputs slow analog inpudoutpue engin... more Type of signals slow digital inpudoutputs fast digital inpudoutputs slow analog inpudoutpue engineering data acquisition channels physics data acquisition channels

Research paper thumbnail of The Tara Control, Monitoring, Data Acquisition, and Analysis System

Fusion Technology 1986, 1986

Experiments at the MIT Tara Tandem Mirror utilize an integrated system for control, monitoring, d... more Experiments at the MIT Tara Tandem Mirror utilize an integrated system for control, monitoring, data acquisition, physics analysis, and archiving. This system consists of two distinct parts with narrowly defined information interchange; one to provide automated control and real time monitoring of engineering functions and one to acquire, analyze, and display data for physics in near real time. Typical machine

Research paper thumbnail of Simplifying FusionGrid security

CLADE 2005. Proceedings Challenges of Large Applications in Distributed Environments, 2005.

Since inception in 2001, FusionGrid developers have worked to secure computational resources in a... more Since inception in 2001, FusionGrid developers have worked to secure computational resources in a multiinstitutional environment with geographically dispersed users. Recent improvements to grid security have streamlined the usage and administration of resources. More than simply increasing security, these improvements have made FusionGrid security easier for resource administrators and the fusion scientists that use FusionGrid, allowing them to get work done with minimal inconvenience. Improvements in authentication, authorization, and data handling have been welcomed by fusion scientists and promise to ease the burden of adding new resources to the grid.

Research paper thumbnail of Data acquisition system for Alcator C-Mod

Review of Scientific Instruments, 1997

The Alcator C-Mod experiment requires an efficient data handling system to acquire and distribute... more The Alcator C-Mod experiment requires an efficient data handling system to acquire and distribute the large number of measurements recorded during each pulse of the tokamak. Over 2000 signals amounting to over 80 megabytes of data are stored and distributed to 40 workstations for display and analysis. With machine pulses occurring every ten to fifteen minutes, most of the information must be distributed within 2-3 minutes after the pulse to enable the experimentalist to adjust the control settings for the next pulse. In addition to the local control room data distribution requirements, the system must also provide data access to remote sites which monitor diagnostics installed on the Alcator C-Mod experiment. This paper will describe the hardware and software used to accomplish this data handling task.

Research paper thumbnail of MDSplus data acquisition system

Review of Scientific Instruments, 1997

MDSplus is made up of a set of X/motif based tools for data acquisition and display, as well as d... more MDSplus is made up of a set of X/motif based tools for data acquisition and display, as well as diagnostic configuration and management. It is based on a hierarchical experiment description which completely describes the data acquisition and analysis tasks and contains the results from these operations. These tools were designed to operate in a distributed, client/server environment with multiple concurrent readers and writers to the data store. While usually used over a Local Area Network, these tools can be used over the Internet to provide access for remote diagnosticians and even machine operators. An interface to a relational database is provided for storage and management of processed data. IDL 1 is used as the primary data analysis and visualization tool.

Research paper thumbnail of TARA data‐acquisition and physics analysis system (abstract)

Review of Scientific Instruments, 1985

The MIT data-acquisition and physics analysis system was designed to provide high throughput and ... more The MIT data-acquisition and physics analysis system was designed to provide high throughput and ready access to data from any run. The system is based on a VAX 11/750 which is to be configured in a VAX cluster back-end network. The front end for the data system is a kinetic system CAMAC serial highway interface. Preexisting software packages have been

Research paper thumbnail of X-windows-based user interface for data acquisition and display

Review of Scientific Instruments, 1990

A Macintosh-like user interface for the MDS-Plus data acquisition system is being implemented usi... more A Macintosh-like user interface for the MDS-Plus data acquisition system is being implemented using the DECwindows MIT/X interface. MDS-Plus is a model driven general purpose data acquisition system being developed collaboratively by the CMOD group at MIT Plasma Fusion Center, the RFX group at IGI-Padua, and the ZTH group at Los Alamos National Laboratory. The model is a hierarchical description of an experiment, including all of the tasks to be performed and the results of having performed them. The inherent complexity of this experimental model requires the users to specify fairly complicated descriptions of what they want the system to do. A ‘‘Point and Click’’ interface simplifies this by presenting to the user a coherent set of choices which are valid in the current context. We are implementing a set of tools for data acquisition and data analysis which use DECwindows to this end. They include a data displayer (Scope Replacement), an experiment model editor (Tree Editor), a timing system, and a waveform editor. These tools provide an easy to use interface to the MDS-Plus data acquisition system.

Research paper thumbnail of Operation Request Gatekeeper: A software system for remote access control of diagnostic instruments in fusion experiments

Review of Scientific Instruments, 2010

Research paper thumbnail of The 2008 Public Release of the International Multi-tokamak Confinement Profile Database

Nuclear Fusion, 2008

This paper documents the public release PR08 of the International Tokamak Physics Activity (ITPA)... more This paper documents the public release PR08 of the International Tokamak Physics Activity (ITPA) profile database, which should be of particular interest to the magnetic confinement fusion community. Data from a wide variety of interesting discharges from many of the world's leading tokamak experiments are now made available in PR08, which also includes predictive simulations of an initial set of operating scenarios for ITER. In this paper we describe the discharges that have been included and the tools that are available to the reader who is interested in accessing and working with the data. Most discharge descriptions refer to more detailed previous publications. In addition, we review physics analyses that have already made use of the profile database discharges. Public access to PR08 data is unconditional, but this paper should be cited by any publication that makes use of PR08 data.

Research paper thumbnail of ROAM: An Authorization Manager for Grids

Journal of Grid Computing, 2006

The Resource Oriented Authorization Manager (ROAM) was created to provide a simple but flexible a... more The Resource Oriented Authorization Manager (ROAM) was created to provide a simple but flexible authorization system for the FusionGrid computational grid. ROAM builds on and extends previous community efforts by both responding to access authorization requests and by providing a Web interface for resource management. ROAM works with the Globus Resource Allocation Manager (GRAM), and is general enough to be used by other virtual organizations that use Globus middleware or X.509/TLS authentication schemes to secure a grid of distributed resources. In addition to describing ROAM, this paper discusses the basic design parameters of a grid authorization system and the reasons for the choices made in the ROAM design.

Research paper thumbnail of Disclaimer

This report was prepared as an account of work sponsored by an agency of the United States Govern... more This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

Research paper thumbnail of Abstract DRAFT COPY (to be published in Journal of Grid Computing) ROAM: An Authorization Manager for Grids

was created to provide a simple but flexible authorization system for the FusionGrid computationa... more was created to provide a simple but flexible authorization system for the FusionGrid computational grid. ROAM builds on and extends previous community efforts by both responding to access authorization requests and by providing a Web interface for resource management. ROAM works with the Globus Resource Allocation Manager (GRAM), and is general enough to be used by other virtual organizations that use Globus middleware or X.509/TLS authentication schemes to secure a grid of distributed resources. In addition to describing ROAM, this paper discusses the basic design parameters of a grid authorization system and the reasons for the choices made in the ROAM design. 1

Research paper thumbnail of Data acquisition system for Alcator

The Alcator C-Mod experiment requires an efficient data handling system to acquire and distribute... more The Alcator C-Mod experiment requires an efficient data handling system to acquire and distribute the large number of measurements recorded during each pulse of the tokamak. Over 2000 signals amounting to over 80 megabytes of data are stored and distributed to 40 workstations for display and analysis. With machine pulses occurring every 10 to 15 min, most of the information must be distributed within 2 to 3 min after the pulse to enable the experimentalist to adjust the control settings for the next pulse. In addition to the local control room data distribution requirements, the system must also provide data access to remote sites which monitor diagnostics installed on the Alcator C-Mod experiment. This article will describe the hardware and software used to accomplish data handling tasks. ©1997 American Institute of Physics. @S0034-6748 ~97!64801-7#

Research paper thumbnail of PFC / JA-96-21 Data Acquisition System for Alcator C-Mod

The Alcator C-Mod experiment requires an efficient data handling system to acquire and distribute... more The Alcator C-Mod experiment requires an efficient data handling system to acquire and distribute the large number of measurements recorded during each pulse of the tokamak. Over 2000 signals amounting to over 80 megabytes of data are stored and distributed to 40 workstations for display and analysis. With machine pulses occurring every ten to fifteen minutes, most of the information must be distributed within 2-3 minutes after the pulse to enable the experimentalist to adjust the control settings for the next pulse. In addition to the local control room data distribution requirements, the system must also provide data access to remote sites which monitor diagnostics installed on the Alcator C-Mod experiment. This paper will describe the hardware and software used to accomplish this data handling task.

Research paper thumbnail of Control and Data Acquisition System for Lower Hybrid Current Drive in Alcator C-Mod

AIP Conference Proceedings, 2003

A lower hybrid current drive (LHCD) system is being installed on the Alcator C-Mod tokamak. Initi... more A lower hybrid current drive (LHCD) system is being installed on the Alcator C-Mod tokamak. Initially, 12 klystrons operating at 4.6 GHz will deliver a total power of 3 MW to the coupler. The LHCD system will make it possible to modify the current density profile in the outer half of the plasma. This implies that the q-profile can be manipulated, thereby enabling the study of advanced tokamak regimes. In this paper we describe the overall structure of the control and data acquisition system for LHCD. The acquisition setup collects data from the active controller, the transmitter protection and the coupler protection systems. Long pulse tests of the klystrons are presented and a monitor camera is introduced.

Research paper thumbnail of Remote Participation of Large-Scale Fusion Experiments

This paper examines the past, present, and future remote operation of large-scale fusion experime... more This paper examines the past, present, and future remote operation of large-scale fusion experiments by large, geographically dispersed teams. The fusion community has considerable experience placing remote collaboration tools in the hands of real users. Tools to remotely view operations and control selected instrumentation and analysis tasks were in use as early as 1992 and full remote operation of an entire tokamak experiment was demonstrated in 1996. Today's experiments invariably involve a mix of local and remote researchers, with sessions routinely led from remote institutions. Currently, the National Fusion Collaboratory Project has created a FusionGrid for secure remote computations and has placed collaborative tools into operating control rooms. Looking towards the future, ITER will be the next major step in the international program. Fusion experiments put a premium on near real-time interactions with data and among members of the team and though ITER will generate more data than current experiments, the greatest challenge will be the provisioning of systems for analyzing, visualizing and assimilating data to support distributed decision making during ITER operation.

Research paper thumbnail of Lessons learned from the MIT Tara control and data system

The control and data system of the MIT Tara Tandem Mirror has worked successfully throughout the ... more The control and data system of the MIT Tara Tandem Mirror has worked successfully throughout the lifetime of the experiment (1983 through 1987). As the Tara project winds down, it is appropriate to summarize the lessons learned from the implementation and operation of the control and data system over the years and in its final form. The control system handled

Research paper thumbnail of SciDAC Fusiongrid Project--A National Collaboratory to Advance the Science of High Temperature Plasma Physics for Magnetic Fusion

Research paper thumbnail of A National Collaboratory to Advance the Science of High Temperature Plasma Physics for Magnetic Fusion

Research paper thumbnail of MDS-PIUS: A Software System for Fast Control and Data Acquisition in Fusion Experiments

Seventh Conference Real Time '91 on Computer Applications in Nuclear, Particle and Plasma Physics Conference Record

ABSTRACT

Research paper thumbnail of Graphical user interface of RFX control and data acquisition system

15th IEEE/NPSS Symposium. Fusion Engineering

Type of signals slow digital inpudoutputs fast digital inpudoutputs slow analog inpudoutpue engin... more Type of signals slow digital inpudoutputs fast digital inpudoutputs slow analog inpudoutpue engineering data acquisition channels physics data acquisition channels

Research paper thumbnail of The Tara Control, Monitoring, Data Acquisition, and Analysis System

Fusion Technology 1986, 1986

Experiments at the MIT Tara Tandem Mirror utilize an integrated system for control, monitoring, d... more Experiments at the MIT Tara Tandem Mirror utilize an integrated system for control, monitoring, data acquisition, physics analysis, and archiving. This system consists of two distinct parts with narrowly defined information interchange; one to provide automated control and real time monitoring of engineering functions and one to acquire, analyze, and display data for physics in near real time. Typical machine

Research paper thumbnail of Simplifying FusionGrid security

CLADE 2005. Proceedings Challenges of Large Applications in Distributed Environments, 2005.

Since inception in 2001, FusionGrid developers have worked to secure computational resources in a... more Since inception in 2001, FusionGrid developers have worked to secure computational resources in a multiinstitutional environment with geographically dispersed users. Recent improvements to grid security have streamlined the usage and administration of resources. More than simply increasing security, these improvements have made FusionGrid security easier for resource administrators and the fusion scientists that use FusionGrid, allowing them to get work done with minimal inconvenience. Improvements in authentication, authorization, and data handling have been welcomed by fusion scientists and promise to ease the burden of adding new resources to the grid.

Research paper thumbnail of Data acquisition system for Alcator C-Mod

Review of Scientific Instruments, 1997

The Alcator C-Mod experiment requires an efficient data handling system to acquire and distribute... more The Alcator C-Mod experiment requires an efficient data handling system to acquire and distribute the large number of measurements recorded during each pulse of the tokamak. Over 2000 signals amounting to over 80 megabytes of data are stored and distributed to 40 workstations for display and analysis. With machine pulses occurring every ten to fifteen minutes, most of the information must be distributed within 2-3 minutes after the pulse to enable the experimentalist to adjust the control settings for the next pulse. In addition to the local control room data distribution requirements, the system must also provide data access to remote sites which monitor diagnostics installed on the Alcator C-Mod experiment. This paper will describe the hardware and software used to accomplish this data handling task.

Research paper thumbnail of MDSplus data acquisition system

Review of Scientific Instruments, 1997

MDSplus is made up of a set of X/motif based tools for data acquisition and display, as well as d... more MDSplus is made up of a set of X/motif based tools for data acquisition and display, as well as diagnostic configuration and management. It is based on a hierarchical experiment description which completely describes the data acquisition and analysis tasks and contains the results from these operations. These tools were designed to operate in a distributed, client/server environment with multiple concurrent readers and writers to the data store. While usually used over a Local Area Network, these tools can be used over the Internet to provide access for remote diagnosticians and even machine operators. An interface to a relational database is provided for storage and management of processed data. IDL 1 is used as the primary data analysis and visualization tool.

Research paper thumbnail of TARA data‐acquisition and physics analysis system (abstract)

Review of Scientific Instruments, 1985

The MIT data-acquisition and physics analysis system was designed to provide high throughput and ... more The MIT data-acquisition and physics analysis system was designed to provide high throughput and ready access to data from any run. The system is based on a VAX 11/750 which is to be configured in a VAX cluster back-end network. The front end for the data system is a kinetic system CAMAC serial highway interface. Preexisting software packages have been

Research paper thumbnail of X-windows-based user interface for data acquisition and display

Review of Scientific Instruments, 1990

A Macintosh-like user interface for the MDS-Plus data acquisition system is being implemented usi... more A Macintosh-like user interface for the MDS-Plus data acquisition system is being implemented using the DECwindows MIT/X interface. MDS-Plus is a model driven general purpose data acquisition system being developed collaboratively by the CMOD group at MIT Plasma Fusion Center, the RFX group at IGI-Padua, and the ZTH group at Los Alamos National Laboratory. The model is a hierarchical description of an experiment, including all of the tasks to be performed and the results of having performed them. The inherent complexity of this experimental model requires the users to specify fairly complicated descriptions of what they want the system to do. A ‘‘Point and Click’’ interface simplifies this by presenting to the user a coherent set of choices which are valid in the current context. We are implementing a set of tools for data acquisition and data analysis which use DECwindows to this end. They include a data displayer (Scope Replacement), an experiment model editor (Tree Editor), a timing system, and a waveform editor. These tools provide an easy to use interface to the MDS-Plus data acquisition system.

Research paper thumbnail of Operation Request Gatekeeper: A software system for remote access control of diagnostic instruments in fusion experiments

Review of Scientific Instruments, 2010

Research paper thumbnail of The 2008 Public Release of the International Multi-tokamak Confinement Profile Database

Nuclear Fusion, 2008

This paper documents the public release PR08 of the International Tokamak Physics Activity (ITPA)... more This paper documents the public release PR08 of the International Tokamak Physics Activity (ITPA) profile database, which should be of particular interest to the magnetic confinement fusion community. Data from a wide variety of interesting discharges from many of the world's leading tokamak experiments are now made available in PR08, which also includes predictive simulations of an initial set of operating scenarios for ITER. In this paper we describe the discharges that have been included and the tools that are available to the reader who is interested in accessing and working with the data. Most discharge descriptions refer to more detailed previous publications. In addition, we review physics analyses that have already made use of the profile database discharges. Public access to PR08 data is unconditional, but this paper should be cited by any publication that makes use of PR08 data.

Research paper thumbnail of ROAM: An Authorization Manager for Grids

Journal of Grid Computing, 2006

The Resource Oriented Authorization Manager (ROAM) was created to provide a simple but flexible a... more The Resource Oriented Authorization Manager (ROAM) was created to provide a simple but flexible authorization system for the FusionGrid computational grid. ROAM builds on and extends previous community efforts by both responding to access authorization requests and by providing a Web interface for resource management. ROAM works with the Globus Resource Allocation Manager (GRAM), and is general enough to be used by other virtual organizations that use Globus middleware or X.509/TLS authentication schemes to secure a grid of distributed resources. In addition to describing ROAM, this paper discusses the basic design parameters of a grid authorization system and the reasons for the choices made in the ROAM design.