title: Effect of the time characteristics of the Compton camera on its performance

authors: Uche, Chibueze Zimuzo

abstract: Purpose: The effect of the time characteristics of the Compton camera data acquisition (DAQ) system on the camera’s performance has been studied. 
Methods: The GEANT4 simulation software was used to simulate radiation transport and interactions with matter. Further investigations were carried out by utilizing straightforward approximations to estimate the charge collection times and their relationship to finding coincident events, setting thresholds to reject noise, and the resultant impacts on the Compton camera performance. 
Results: The results show that the time characteristics of the Compton camera DAQ account for about 17% and 13% reduction in detection efficiency at 140.5 keV and 511 keV, respectively, but made no significant difference on the Compton camera resolution.
Conclusions: Findings suggest that the detection efficiency of the Compton camera has been overestimated by previous investigators who did not predict count rate losses under clinical conditions.

text: Effect of the time characteristics of the Compton camera on its performance Purpose: The effect of the time characteristics of the Compton camera data acquisition (DAQ) system on the camera’s performance has been studied. 
Methods: The GEANT4 simulation software was used to simulate radiation transport and interactions with matter. Further investigations were carried out by utilizing straightforward approximations to estimate the charge collection times and their relationship to finding coincident events, setting thresholds to reject noise, and the resultant impacts on the Compton camera performance. 
Results: The results show that the time characteristics of the Compton camera DAQ account for about 17% and 13% reduction in detection efficiency at 140.5 keV and 511 keV, respectively, but made no significant difference on the Compton camera resolution.
Conclusions: Findings suggest that the detection efficiency of the Compton camera has been overestimated by previous investigators who did not predict count rate losses under clinical conditions.

year: 2011

title: Displaying 3D images: algorithms for single-image random-dot

authors: Thimbleby, Harold W.

subjects: Machine learning

abstract: A new, simple, and symmetric algorithm can be implemented that results in higher levels of detail in solid objects than previously possible with autostereograms. In a stereoscope, an optical instrument similar to binoculars, each eye views a different picture and thereby receives the specific image that would have arisen naturally. An early suggestion for a color stereo computer display involved a rotating filter wheel held in front of the eyes. In contrast, this article describes a method for viewing on paper or on an ordinary computer screen without special equipment, although it is limited to the display of 3D monochromatic objects. (The image can be colored, say, for artistic reasons, but the method we describe does not allow colors to be allocated in a way that corresponds to an arbitrary coloring of the solid object depicted.) The image can easily be constructed by computer from any 3D scene or solid object description.

text: Displaying 3D images: algorithms for single-image random-dot A new, simple, and symmetric algorithm can be implemented that results in higher levels of detail in solid objects than previously possible with autostereograms. In a stereoscope, an optical instrument similar to binoculars, each eye views a different picture and thereby receives the specific image that would have arisen naturally. An early suggestion for a color stereo computer display involved a rotating filter wheel held in front of the eyes. In contrast, this article describes a method for viewing on paper or on an ordinary computer screen without special equipment, although it is limited to the display of 3D monochromatic objects. (The image can be colored, say, for artistic reasons, but the method we describe does not allow colors to be allocated in a way that corresponds to an arbitrary coloring of the solid object depicted.) The image can easily be constructed by computer from any 3D scene or solid object description.

year: 1994-10-01

title: He Matapihi Mā Mua, Mō Muri: The Ethics, Processes, and Procedures Associated with the Digitization of Indigenous Knowledge—The Pei Jones Collection

authors: Whaanga, Hēmi

abstract: The digital era has transformed how people live their lives and interact with the world and knowledge systems around them. In Aotearoa/New Zealand a range of initiatives incorporating Indigenous knowledge have been implemented to collect, catalog, maintain, and organize digital objects. In this article, we report on the ethics, processes, and procedures associated with the digitization of the manuscripts, works, and collected taonga (treasures) of the late Dr. Pei Te Hurinui Jones—and describe how it was transformed into a digital library. It discusses the decision-making processes and the various roles and responsibilities of the researchers, family members, and institute in this process.

text: He Matapihi Mā Mua, Mō Muri: The Ethics, Processes, and Procedures Associated with the Digitization of Indigenous Knowledge—The Pei Jones Collection The digital era has transformed how people live their lives and interact with the world and knowledge systems around them. In Aotearoa/New Zealand a range of initiatives incorporating Indigenous knowledge have been implemented to collect, catalog, maintain, and organize digital objects. In this article, we report on the ethics, processes, and procedures associated with the digitization of the manuscripts, works, and collected taonga (treasures) of the late Dr. Pei Te Hurinui Jones—and describe how it was transformed into a digital library. It discusses the decision-making processes and the various roles and responsibilities of the researchers, family members, and institute in this process.

year: 2015