John Winans | Northern Illinois University (original) (raw)
Papers by John Winans
The Advanced Photon Source (APS) control system is based on a distributed topology of microproces... more The Advanced Photon Source (APS) control system is based on a distributed topology of microprocessor–based Input/Output Controllers (IOCs). Since the cost effectiveness of placing an IOC near every point where an interface to the control system is required may be prohibitive, I/O subnets implemented via mes-sage passing network protocols are utilized. For greatest flexi-bility, such a subnet must support connections to equipment via discrete I/O points, connections to standard interfaces such as GPIB and RS232, and be a practical network for custom–de-signed interfaces to intelligent equipment. This paper describes the BITBUS Universal Gateway (BUG), a device which sup-ports the different interfaces mentioned above with a connection to a single BITBUS distributed subnet. The BUG utilizes an in-terchangeable set of circuit boards, which allow for a commonal-
arXiv: Medical Physics, 2020
Verification of patient specific proton stopping powers obtained in the patient treatment positio... more Verification of patient specific proton stopping powers obtained in the patient treatment position can be used to reduce the distal margins needed in particle beam planning. Proton radiography can be used as a pre-treatment instrument to verify integrated stopping power consistency with the treatment planning CT. Although a proton radiograph is a pixel by pixel representation of integrated stopping powers, the image may also be of high enough quality and contrast to be used for patient alignment. This investigation qualifies the accuracy and image quality of a prototype proton radiography system on a clinical proton delivery system. We have developed a clinical prototype proton radiography system designed for integration into efficient clinical workflows. We tested the images obtained by this system for water-equivalent thickness (WET) accuracy, image noise, and spatial resolution. We evaluated the WET accuracy by comparing the average WET and rms error in several regions of interes...
arXiv: Medical Physics, 2020
Purpose: To demonstrate a proton imaging system based on well-established fast scintillator techn... more Purpose: To demonstrate a proton imaging system based on well-established fast scintillator technology to achieve high performance with low cost and complexity, with the potential of a straightforward translation into clinical use. Methods: The system tracks individual protons through one (X, Y) scintillating fiber tracker plane upstream and downstream of the object and into a 13 cm-thick scintillating block residual energy detector. The fibers in the tracker planes are multiplexed into silicon photomultipliers (SiPMs) to reduce the number of electronics channels. The light signal from the residual energy detector is collected by 16 photomultiplier tubes (PMTs). Only four signals from the PMTs are output from each event, which allows for fast signal readout. A robust calibration method of the PMT signal to residual energy has been developed to obtain accurate proton images. The development of patient-specific scan patterns using multiple input energies allows for an image to be prod...
Medical Physics, 2021
Purpose: Verification of patient specific proton stopping powers obtained in the patient's treatm... more Purpose: Verification of patient specific proton stopping powers obtained in the patient's treatment position can be used to reduce the distal and proximal margins needed in particle beam planning. Proton radiography can be used as a pre-treatment instrument to verify integrated stopping power consistency with the treatment planning CT. Although a proton radiograph is a pixel by pixel representation of integrated stopping powers, the image may also be of high enough quality and contrast to be used for patient alignment. This investigation quantifies the accuracy and image quality of a prototype proton radiography system on a clinical proton delivery system. Methods: We have developed a clinical prototype proton radiography system designed for integration into efficient clinical workflows. We tested the images obtained by this system for water-equivalent thickness (WET) accuracy, image noise, and spatial resolution. We evaluated the WET accuracy by comparing the average WET and rms error in several regions of interest (ROI) on a proton radiograph of a custom peg phantom. We measured the spatial resolution on a CATPHAN Line Pair phantom and a custom edge phantom by measuring the 10% value of the modulation transfer function (MTF). In addition, we tested the ability to detect proton range errors due to anatomical changes in a patient with a customized CIRS pediatric head phantom and inserts of varying WET placed in the posterior fossae of the brain. We took proton radiographs of the phantom with each insert in place and created difference maps between the resulting images. Integrated proton range was measured from an ROI in the difference maps. Results: We measured the WET accuracy of the proton radiographic images to be ±0.2 mm (0.33%) from known values. The spatial resolution of the images was 0.6 lp/mm on the line pair phantom and 1.13 lp/mm on the edge phantom. We were able to detect anatomical changes producing changes in WET as low as 0.6 mm. Conclusion: The proton radiography system produces images with image quality sufficient for pretreatment range consistency verification.
Medical Physics, 2021
Purpose: Currently, calculations of proton range in proton therapy patients are based on a conver... more Purpose: Currently, calculations of proton range in proton therapy patients are based on a conversion of CT Hounsfield Units of patient tissues into proton relative stopping power. Uncertainties in this conversion necessitate larger proximal and distal planned target volume margins. Proton CT can potentially reduce these uncertainties by directly measuring proton stopping power. We aim to demonstrate proton CT imaging with complex porcine samples, to analyze in detail three-dimensional regions of interest, and to compare proton stopping powers directly measured by proton CT to those determined from x-ray CT scans. Methods: We have used a prototype proton imaging system with single proton tracking to acquire proton radiography and proton CT images of a sample of porcine pectoral girdle and ribs, and a pig's head. We also acquired close in time x-ray CT scans of the same samples, and compared proton stopping power measurements from the two modalities. In the case of the pig's head, we obtained x-ray CT scans from two different scanners, and compared results from high-dose and low-dose settings. Results: Comparing our reconstructed proton CT images with images derived from x-ray CT scans, we find agreement within 1% to 2% for soft tissues, and discrepancies of up to 6% for compact bone. We also observed large discrepancies, up to 40%, for i
International Journal of Radiation Oncology*Biology*Physics, 2017
Purpose/Objective(s): Margin reduction and hypo-fractionated treatment of pancreatic cancer is in... more Purpose/Objective(s): Margin reduction and hypo-fractionated treatment of pancreatic cancer is increasing in interest and practice in radiation oncology, but pancreatic motion has the potential to limit clinical efficacy. This study details the magnitude of observed positional variations of pancreatic tumors treated with radiation therapy utilizing the results of daily image guided radiation therapy (IGRT). Materials/Methods: Daily IGRT shifts based on cone-beam CT (CBCT) and mega-voltage CT (MVCT) were recorded and evaluated in order to estimate positioning variations of pancreatic target volumes. A total of 72 patients and 1159 3D-images captured immediately prior to daily conventionally fractionated RT were considered. Overall positioning variations, inter-patient variations, and correlations between position variations and patient-specific factors including PTV volume, tumor location (head/body/tail of pancreas), and central or lateral positioning of the PTV were estimated. Statistical analysis of the positioning variations included Kolmogorov-Smirnov (KS) testing for normality of distributions. Estimation of appropriate margins was carried out based on MZ2.5S+0.7s assuming the measured inter-fraction shifts are representative of intrafraction motion, and present a conservative estimate of spatial expansions to ensure coverage of the CTV. Results: Mean and standard deviation of IGRT shifts for all patients was 0.2AE5.2 mm in lateral directions,-0.3AE4.3 mm in vertical directions, and-0.7AE5.5 mm in longitudinal directions. The systematic variation (the standard deviation of inter-patient average shifts) was 2.6 mm, 2.6 mm, and 3.0 mm in lateral, vertical, and longitudinal directions. The random variation (the average of inter-patient standard deviations) was 3.9 mm, 3.0 mm, and 4.1 mm lateral, vertical, and longitudinal directions. Combined, these results suggest uniform margins about the CTV up to 10.4 mm are sufficient to account for observed positioning variations during IGRT. For each patient, KS testing implies the patient-specific shifts were representative of Gaussian distributions for 70/72 patients and 2/216 patient-specific directional distributions. The patient-specific distributions were not correlated with PTV volume, central or lateral location of the PTV, or whether the tumor was in the pancreatic head, tail, or body. Conclusion: Pancreas is a mobile organ with potential for large motion; our results suggest this motion is normally distributed and well-represented by Gaussian distributions. If intra-and inter-fraction motion are similar, which is plausible if pancreas motion is due to breathing and gastrointestinal motion, our data suggest margins of 10.4 mm will account for these spatial variations. These margins will surely overlap with surrounding bowel, duodenum, and/or stomach and imply dose escalation of margin-based PTVs may not be feasible.
GPU-based computing has gained popularity in recent years due to its growing software support and... more GPU-based computing has gained popularity in recent years due to its growing software support and greater processing capabilities than its CPU counterpart. GPU computing was recently added in the finite-difference timedomain program VORPAL. In this paper we carry electromagnetic simulations through a slab-symmetric dielectriclined waveguide (DLW). We use this simulation model to explore the scaling of the GPU version of VORPAL on a new TOP1000-grade hybrid GPU/CPU computer cluster available at Northern Illinois University (NIU).
The Advanced Photon Source (APS), now under construction at Argonne National Laboratory is a 7 Ge... more The Advanced Photon Source (APS), now under construction at Argonne National Laboratory is a 7 GeV positron storage ring dedicated to research facilities using synchrotron radiation. This ring, along with its injection accelerators is to be controlled and monitored with a single, flexible, and expandable control system. In the conceptual stage the control system design group faced the challenges that
ABSTRACT A remotely operated vehicle (ROV) has been custom-designed and built by DOER Marine to m... more ABSTRACT A remotely operated vehicle (ROV) has been custom-designed and built by DOER Marine to meet scientific requirements for exploring subglacial water cavities. This sub-ice rover (SIR) will explore and quantitatively document the grounding zone areas of the Ross Ice Shelf cavity using a 3km-long umbilical tether by deployment through an 800m-long ice borehole in a torpedo shape, which is also its default mode if operational failure occurs. Once in the ocean cavity it transforms via a diamond-shaped geometry into a rectangular form when all of its instruments come alive in its flight mode. Instrumentation includes 4 cameras (one forward-looking HD), a vertical scanning sonar (long-range imaging for spatial orientation and navigation), Doppler current meter (determine water current velocities), multi-beam sonar (image and swath map bottom topography), sub-bottom profiler (profile sub-sea-floor sediment for geological history), CTD (determine salinity, temperature and depth), DO meter (determine dissolved oxygen content in water), transmissometer (determine suspended particulate concentrations in water), laser particle-size analyzer (determine sizes of particles in water), triple laser-beams (determine size and volume of objects), thermistor probe (measure in situ temperatures of ice and sediment), shear vane probe (determine in situ strength of sediment), manipulator arm (deploy instrumentation packages, collect samples), shallow ice corer (collect ice samples and glacial debris), water sampler (determine sea water/freshwater composition, calibrate real-time sensors, sample microbes), shallow sediment corer (sample sea floor, in-ice and subglacial sediment for stratigraphy, facies, particle size, composition, structure, fabric, microbes). A sophisticated array of data handling, storing and displaying will allow real-time observations and environmental assessments to be made. This robotic submarine and other instruments will be tested in Lake Tahoe in September, 2011 and results will be presented on its trials and geological and biological findings down to the deepest depths of the lake. Other instruments include a 5m-ling percussion corer for sampling deeper sediments, an ice-tethered profiler with CTD and ACDP, and in situ oceanographic mooring designed to fit down a narrow (30cm-diameter) ice borehole that include interchangeable packages of ACDPs, CTDs, transmissometers, laser particle-size analyzer, DO meter, automated multi-port water sampler, water column nutrient analyzer, sediment porewater chemistry analyzer, down-looking color camera (see figure), and altimeter.
International Journal of Radiation Oncology*Biology*Physics
Annals of Glaciology
The Subglacial Antarctic Lakes Scientific Access (SALSA) Project accessed Mercer Subglacial Lake ... more The Subglacial Antarctic Lakes Scientific Access (SALSA) Project accessed Mercer Subglacial Lake using environmentally clean hot-water drilling to examine interactions among ice, water, sediment, rock, microbes and carbon reservoirs within the lake water column and underlying sediments. A ~0.4 m diameter borehole was melted through 1087 m of ice and maintained over ~10 days, allowing observation of ice properties and collection of water and sediment with various tools. Over this period, SALSA collected: 60 L of lake water and 10 L of deep borehole water; microbes >0.2 μm in diameter from in situ filtration of ~100 L of lake water; 10 multicores 0.32–0.49 m long; 1.0 and 1.76 m long gravity cores; three conductivity–temperature–depth profiles of borehole and lake water; five discrete depth current meter measurements in the lake and images of ice, the lake water–ice interface and lake sediments. Temperature and conductivity data showed the hydrodynamic character of water mixing bet...
Journal of Radiation Oncology
Journal of Radiation Oncology
Area detector based photon correlation in the regime of short data batches: Data reduction for dy... more Area detector based photon correlation in the regime of short data batches: Data reduction for dynamic x-ray scattering Review of Scientific Instruments 71, 3274 (2000);
TheAdvancedPhotonSource(APS) control system is based on a distributed topology of microprocessor-... more TheAdvancedPhotonSource(APS) control system is based on a distributed topology of microprocessor--based Input/Output Controllers (IOCs). Since the cost effectiveness of placing an IOC near every point where an interface to the control system is required may be prohibitive, I/O subnets implemented via message passing network protocols are utilized. For greatest flexibility, such a subnet must support connections to equipment via discrete I/O points, connections to standard interfaces such as GPIB and RS232, and be a practical network for custom--designed interfaces to intelligent equipment. This paper describes the BITBUS Universal Gateway (BUG), a device which supports the different interfaces mentioned above with a connection to a single BITBUS distributed subnet. The BUG utilizes an interchangeable set of circuit boards, which allow for a commonality among interface points, and the ability to use commercially-- available modules for I/O. This approach also circumvents several limi...
IEEE Transactions on Cloud Computing, 2015
Proceedings of International Conference on Particle Accelerators, 1993
The Advanced Photon Source (APS) control system is based on a distributed topology of microproces... more The Advanced Photon Source (APS) control system is based on a distributed topology of microprocessor-based Input/Output Controllers (IO&). Since the cost effectiveness of placing an IOC near every point where an interface to the control system is required may he prohibitive, I/O subnets implemented via message passing network protocols are utilized. For greatest flexibility, such a subnet must support connections to equipment via discrete I/O points, connections to standard interfaces such as GPIB and RS232, and be a practical network for custom-designed interfaces to intelligent equipment. This paper describes the BITBUS Universal Gateway (BUG), a device which supports the different interfaces mentioned above with a connection to a single BITBUS distributed subnet. The BUG utilizes an interchangeable set of circuit boards, which allow for acommonality among interface points, and the ability to use commerciallyavailable modules for I/O. This approach also circumvents several limitations of GPIB and RS232, which restrict their use in industrial, electrically harsh environments, via an implementation of the BITBUS protocol over optical fibers.
The Advanced Photon Source (APS) control system is based on a distributed topology of microproces... more The Advanced Photon Source (APS) control system is based on a distributed topology of microprocessor–based Input/Output Controllers (IOCs). Since the cost effectiveness of placing an IOC near every point where an interface to the control system is required may be prohibitive, I/O subnets implemented via mes-sage passing network protocols are utilized. For greatest flexi-bility, such a subnet must support connections to equipment via discrete I/O points, connections to standard interfaces such as GPIB and RS232, and be a practical network for custom–de-signed interfaces to intelligent equipment. This paper describes the BITBUS Universal Gateway (BUG), a device which sup-ports the different interfaces mentioned above with a connection to a single BITBUS distributed subnet. The BUG utilizes an in-terchangeable set of circuit boards, which allow for a commonal-
arXiv: Medical Physics, 2020
Verification of patient specific proton stopping powers obtained in the patient treatment positio... more Verification of patient specific proton stopping powers obtained in the patient treatment position can be used to reduce the distal margins needed in particle beam planning. Proton radiography can be used as a pre-treatment instrument to verify integrated stopping power consistency with the treatment planning CT. Although a proton radiograph is a pixel by pixel representation of integrated stopping powers, the image may also be of high enough quality and contrast to be used for patient alignment. This investigation qualifies the accuracy and image quality of a prototype proton radiography system on a clinical proton delivery system. We have developed a clinical prototype proton radiography system designed for integration into efficient clinical workflows. We tested the images obtained by this system for water-equivalent thickness (WET) accuracy, image noise, and spatial resolution. We evaluated the WET accuracy by comparing the average WET and rms error in several regions of interes...
arXiv: Medical Physics, 2020
Purpose: To demonstrate a proton imaging system based on well-established fast scintillator techn... more Purpose: To demonstrate a proton imaging system based on well-established fast scintillator technology to achieve high performance with low cost and complexity, with the potential of a straightforward translation into clinical use. Methods: The system tracks individual protons through one (X, Y) scintillating fiber tracker plane upstream and downstream of the object and into a 13 cm-thick scintillating block residual energy detector. The fibers in the tracker planes are multiplexed into silicon photomultipliers (SiPMs) to reduce the number of electronics channels. The light signal from the residual energy detector is collected by 16 photomultiplier tubes (PMTs). Only four signals from the PMTs are output from each event, which allows for fast signal readout. A robust calibration method of the PMT signal to residual energy has been developed to obtain accurate proton images. The development of patient-specific scan patterns using multiple input energies allows for an image to be prod...
Medical Physics, 2021
Purpose: Verification of patient specific proton stopping powers obtained in the patient's treatm... more Purpose: Verification of patient specific proton stopping powers obtained in the patient's treatment position can be used to reduce the distal and proximal margins needed in particle beam planning. Proton radiography can be used as a pre-treatment instrument to verify integrated stopping power consistency with the treatment planning CT. Although a proton radiograph is a pixel by pixel representation of integrated stopping powers, the image may also be of high enough quality and contrast to be used for patient alignment. This investigation quantifies the accuracy and image quality of a prototype proton radiography system on a clinical proton delivery system. Methods: We have developed a clinical prototype proton radiography system designed for integration into efficient clinical workflows. We tested the images obtained by this system for water-equivalent thickness (WET) accuracy, image noise, and spatial resolution. We evaluated the WET accuracy by comparing the average WET and rms error in several regions of interest (ROI) on a proton radiograph of a custom peg phantom. We measured the spatial resolution on a CATPHAN Line Pair phantom and a custom edge phantom by measuring the 10% value of the modulation transfer function (MTF). In addition, we tested the ability to detect proton range errors due to anatomical changes in a patient with a customized CIRS pediatric head phantom and inserts of varying WET placed in the posterior fossae of the brain. We took proton radiographs of the phantom with each insert in place and created difference maps between the resulting images. Integrated proton range was measured from an ROI in the difference maps. Results: We measured the WET accuracy of the proton radiographic images to be ±0.2 mm (0.33%) from known values. The spatial resolution of the images was 0.6 lp/mm on the line pair phantom and 1.13 lp/mm on the edge phantom. We were able to detect anatomical changes producing changes in WET as low as 0.6 mm. Conclusion: The proton radiography system produces images with image quality sufficient for pretreatment range consistency verification.
Medical Physics, 2021
Purpose: Currently, calculations of proton range in proton therapy patients are based on a conver... more Purpose: Currently, calculations of proton range in proton therapy patients are based on a conversion of CT Hounsfield Units of patient tissues into proton relative stopping power. Uncertainties in this conversion necessitate larger proximal and distal planned target volume margins. Proton CT can potentially reduce these uncertainties by directly measuring proton stopping power. We aim to demonstrate proton CT imaging with complex porcine samples, to analyze in detail three-dimensional regions of interest, and to compare proton stopping powers directly measured by proton CT to those determined from x-ray CT scans. Methods: We have used a prototype proton imaging system with single proton tracking to acquire proton radiography and proton CT images of a sample of porcine pectoral girdle and ribs, and a pig's head. We also acquired close in time x-ray CT scans of the same samples, and compared proton stopping power measurements from the two modalities. In the case of the pig's head, we obtained x-ray CT scans from two different scanners, and compared results from high-dose and low-dose settings. Results: Comparing our reconstructed proton CT images with images derived from x-ray CT scans, we find agreement within 1% to 2% for soft tissues, and discrepancies of up to 6% for compact bone. We also observed large discrepancies, up to 40%, for i
International Journal of Radiation Oncology*Biology*Physics, 2017
Purpose/Objective(s): Margin reduction and hypo-fractionated treatment of pancreatic cancer is in... more Purpose/Objective(s): Margin reduction and hypo-fractionated treatment of pancreatic cancer is increasing in interest and practice in radiation oncology, but pancreatic motion has the potential to limit clinical efficacy. This study details the magnitude of observed positional variations of pancreatic tumors treated with radiation therapy utilizing the results of daily image guided radiation therapy (IGRT). Materials/Methods: Daily IGRT shifts based on cone-beam CT (CBCT) and mega-voltage CT (MVCT) were recorded and evaluated in order to estimate positioning variations of pancreatic target volumes. A total of 72 patients and 1159 3D-images captured immediately prior to daily conventionally fractionated RT were considered. Overall positioning variations, inter-patient variations, and correlations between position variations and patient-specific factors including PTV volume, tumor location (head/body/tail of pancreas), and central or lateral positioning of the PTV were estimated. Statistical analysis of the positioning variations included Kolmogorov-Smirnov (KS) testing for normality of distributions. Estimation of appropriate margins was carried out based on MZ2.5S+0.7s assuming the measured inter-fraction shifts are representative of intrafraction motion, and present a conservative estimate of spatial expansions to ensure coverage of the CTV. Results: Mean and standard deviation of IGRT shifts for all patients was 0.2AE5.2 mm in lateral directions,-0.3AE4.3 mm in vertical directions, and-0.7AE5.5 mm in longitudinal directions. The systematic variation (the standard deviation of inter-patient average shifts) was 2.6 mm, 2.6 mm, and 3.0 mm in lateral, vertical, and longitudinal directions. The random variation (the average of inter-patient standard deviations) was 3.9 mm, 3.0 mm, and 4.1 mm lateral, vertical, and longitudinal directions. Combined, these results suggest uniform margins about the CTV up to 10.4 mm are sufficient to account for observed positioning variations during IGRT. For each patient, KS testing implies the patient-specific shifts were representative of Gaussian distributions for 70/72 patients and 2/216 patient-specific directional distributions. The patient-specific distributions were not correlated with PTV volume, central or lateral location of the PTV, or whether the tumor was in the pancreatic head, tail, or body. Conclusion: Pancreas is a mobile organ with potential for large motion; our results suggest this motion is normally distributed and well-represented by Gaussian distributions. If intra-and inter-fraction motion are similar, which is plausible if pancreas motion is due to breathing and gastrointestinal motion, our data suggest margins of 10.4 mm will account for these spatial variations. These margins will surely overlap with surrounding bowel, duodenum, and/or stomach and imply dose escalation of margin-based PTVs may not be feasible.
GPU-based computing has gained popularity in recent years due to its growing software support and... more GPU-based computing has gained popularity in recent years due to its growing software support and greater processing capabilities than its CPU counterpart. GPU computing was recently added in the finite-difference timedomain program VORPAL. In this paper we carry electromagnetic simulations through a slab-symmetric dielectriclined waveguide (DLW). We use this simulation model to explore the scaling of the GPU version of VORPAL on a new TOP1000-grade hybrid GPU/CPU computer cluster available at Northern Illinois University (NIU).
The Advanced Photon Source (APS), now under construction at Argonne National Laboratory is a 7 Ge... more The Advanced Photon Source (APS), now under construction at Argonne National Laboratory is a 7 GeV positron storage ring dedicated to research facilities using synchrotron radiation. This ring, along with its injection accelerators is to be controlled and monitored with a single, flexible, and expandable control system. In the conceptual stage the control system design group faced the challenges that
ABSTRACT A remotely operated vehicle (ROV) has been custom-designed and built by DOER Marine to m... more ABSTRACT A remotely operated vehicle (ROV) has been custom-designed and built by DOER Marine to meet scientific requirements for exploring subglacial water cavities. This sub-ice rover (SIR) will explore and quantitatively document the grounding zone areas of the Ross Ice Shelf cavity using a 3km-long umbilical tether by deployment through an 800m-long ice borehole in a torpedo shape, which is also its default mode if operational failure occurs. Once in the ocean cavity it transforms via a diamond-shaped geometry into a rectangular form when all of its instruments come alive in its flight mode. Instrumentation includes 4 cameras (one forward-looking HD), a vertical scanning sonar (long-range imaging for spatial orientation and navigation), Doppler current meter (determine water current velocities), multi-beam sonar (image and swath map bottom topography), sub-bottom profiler (profile sub-sea-floor sediment for geological history), CTD (determine salinity, temperature and depth), DO meter (determine dissolved oxygen content in water), transmissometer (determine suspended particulate concentrations in water), laser particle-size analyzer (determine sizes of particles in water), triple laser-beams (determine size and volume of objects), thermistor probe (measure in situ temperatures of ice and sediment), shear vane probe (determine in situ strength of sediment), manipulator arm (deploy instrumentation packages, collect samples), shallow ice corer (collect ice samples and glacial debris), water sampler (determine sea water/freshwater composition, calibrate real-time sensors, sample microbes), shallow sediment corer (sample sea floor, in-ice and subglacial sediment for stratigraphy, facies, particle size, composition, structure, fabric, microbes). A sophisticated array of data handling, storing and displaying will allow real-time observations and environmental assessments to be made. This robotic submarine and other instruments will be tested in Lake Tahoe in September, 2011 and results will be presented on its trials and geological and biological findings down to the deepest depths of the lake. Other instruments include a 5m-ling percussion corer for sampling deeper sediments, an ice-tethered profiler with CTD and ACDP, and in situ oceanographic mooring designed to fit down a narrow (30cm-diameter) ice borehole that include interchangeable packages of ACDPs, CTDs, transmissometers, laser particle-size analyzer, DO meter, automated multi-port water sampler, water column nutrient analyzer, sediment porewater chemistry analyzer, down-looking color camera (see figure), and altimeter.
International Journal of Radiation Oncology*Biology*Physics
Annals of Glaciology
The Subglacial Antarctic Lakes Scientific Access (SALSA) Project accessed Mercer Subglacial Lake ... more The Subglacial Antarctic Lakes Scientific Access (SALSA) Project accessed Mercer Subglacial Lake using environmentally clean hot-water drilling to examine interactions among ice, water, sediment, rock, microbes and carbon reservoirs within the lake water column and underlying sediments. A ~0.4 m diameter borehole was melted through 1087 m of ice and maintained over ~10 days, allowing observation of ice properties and collection of water and sediment with various tools. Over this period, SALSA collected: 60 L of lake water and 10 L of deep borehole water; microbes >0.2 μm in diameter from in situ filtration of ~100 L of lake water; 10 multicores 0.32–0.49 m long; 1.0 and 1.76 m long gravity cores; three conductivity–temperature–depth profiles of borehole and lake water; five discrete depth current meter measurements in the lake and images of ice, the lake water–ice interface and lake sediments. Temperature and conductivity data showed the hydrodynamic character of water mixing bet...
Journal of Radiation Oncology
Journal of Radiation Oncology
Area detector based photon correlation in the regime of short data batches: Data reduction for dy... more Area detector based photon correlation in the regime of short data batches: Data reduction for dynamic x-ray scattering Review of Scientific Instruments 71, 3274 (2000);
TheAdvancedPhotonSource(APS) control system is based on a distributed topology of microprocessor-... more TheAdvancedPhotonSource(APS) control system is based on a distributed topology of microprocessor--based Input/Output Controllers (IOCs). Since the cost effectiveness of placing an IOC near every point where an interface to the control system is required may be prohibitive, I/O subnets implemented via message passing network protocols are utilized. For greatest flexibility, such a subnet must support connections to equipment via discrete I/O points, connections to standard interfaces such as GPIB and RS232, and be a practical network for custom--designed interfaces to intelligent equipment. This paper describes the BITBUS Universal Gateway (BUG), a device which supports the different interfaces mentioned above with a connection to a single BITBUS distributed subnet. The BUG utilizes an interchangeable set of circuit boards, which allow for a commonality among interface points, and the ability to use commercially-- available modules for I/O. This approach also circumvents several limi...
IEEE Transactions on Cloud Computing, 2015
Proceedings of International Conference on Particle Accelerators, 1993
The Advanced Photon Source (APS) control system is based on a distributed topology of microproces... more The Advanced Photon Source (APS) control system is based on a distributed topology of microprocessor-based Input/Output Controllers (IO&). Since the cost effectiveness of placing an IOC near every point where an interface to the control system is required may he prohibitive, I/O subnets implemented via message passing network protocols are utilized. For greatest flexibility, such a subnet must support connections to equipment via discrete I/O points, connections to standard interfaces such as GPIB and RS232, and be a practical network for custom-designed interfaces to intelligent equipment. This paper describes the BITBUS Universal Gateway (BUG), a device which supports the different interfaces mentioned above with a connection to a single BITBUS distributed subnet. The BUG utilizes an interchangeable set of circuit boards, which allow for acommonality among interface points, and the ability to use commerciallyavailable modules for I/O. This approach also circumvents several limitations of GPIB and RS232, which restrict their use in industrial, electrically harsh environments, via an implementation of the BITBUS protocol over optical fibers.