title: Entropies of the EEG: The effects of general anaesthesia

authors: Sleigh, James W.

subjects: anaesthesia

abstract: The aim of this paper was to compare the performance of different entropy estimators when applied to EEG data taken from patients during routine induction of general anesthesia. The question then arose as to how and why different EEG patterns could affect the different estimators. Therefore we also compared how the different entropy estimators responded to artificially generated signals with predetermined, known, characteristics. This was done by applying the entropy algorithms to pseudoEEG data:
(1) computer-generated using a second-order autoregressive (AR2) model,
(2) computer-generated white noise added to step signals simulating blink and eyemovement artifacts and,
(3) seeing the effect of exogenous (computer-generated) sine-wave oscillations added to the actual clinically-derived EEG data set from patients undergoing induction of anesthesia.

text: Entropies of the EEG: The effects of general anaesthesia The aim of this paper was to compare the performance of different entropy estimators when applied to EEG data taken from patients during routine induction of general anesthesia. The question then arose as to how and why different EEG patterns could affect the different estimators. Therefore we also compared how the different entropy estimators responded to artificially generated signals with predetermined, known, characteristics. This was done by applying the entropy algorithms to pseudoEEG data:
(1) computer-generated using a second-order autoregressive (AR2) model,
(2) computer-generated white noise added to step signals simulating blink and eyemovement artifacts and,
(3) seeing the effect of exogenous (computer-generated) sine-wave oscillations added to the actual clinically-derived EEG data set from patients undergoing induction of anesthesia.

year: 2001-06

title: Precision crystal frequency reference disciplined using mains power

authors: Dirks, Sam

subjects: Clocks

abstract: We describe a clock that keeps time and provides a reference frequency with better than 1PPM accuracy, through a quartz crystal automatically calibrated via the power line frequency. The long-term precision of line-frequency-based time is used to correct the crystal-based timekeeping system, a process referred to as disciplining. A microcontroller calibrates the internal reference dynamically with no user assistance. Precision is improved to better than 1ppm as measured against a rubidium standard. The precise signal is useful for calibrating frequencybased instrumentation or keeping time without periodic correction and costs much less than comparable alternatives. The algorithm can be implemented in any mains-powered device using a microcontroller, such as thermostats and lighting timers. The prototype clock uses a Nixie-tube display, requires no transformer, is housed a glass tube, and is offered as an opensource design.

text: Precision crystal frequency reference disciplined using mains power We describe a clock that keeps time and provides a reference frequency with better than 1PPM accuracy, through a quartz crystal automatically calibrated via the power line frequency. The long-term precision of line-frequency-based time is used to correct the crystal-based timekeeping system, a process referred to as disciplining. A microcontroller calibrates the internal reference dynamically with no user assistance. Precision is improved to better than 1ppm as measured against a rubidium standard. The precise signal is useful for calibrating frequencybased instrumentation or keeping time without periodic correction and costs much less than comparable alternatives. The algorithm can be implemented in any mains-powered device using a microcontroller, such as thermostats and lighting timers. The prototype clock uses a Nixie-tube display, requires no transformer, is housed a glass tube, and is offered as an opensource design.

year: 2016

title: A Māori homeless woman

authors: Groot, Shiloh Ann Maree

subjects: Māori

abstract: Indigenous peoples are overrepresented in homeless populations in many countries. As part of a larger ethnographic project, this case study draws upon interviews and photoelicitation projects with a homeless Māori woman, Ariā. The actions of this Māori woman exemplify how Indigenous cultural practices can shape a person’s efforts to retain a positive sense of self and place while homeless. Māori cultural concepts relating to caring, leadership, unity, relationships, spirituality, history and place provide a basis for interpreting Ariā’s actions. This article demonstrates the appropriateness of cultural concepts indigenous to a group for conducting ethnographic research into homelessness within that group.

text: A Māori homeless woman Indigenous peoples are overrepresented in homeless populations in many countries. As part of a larger ethnographic project, this case study draws upon interviews and photoelicitation projects with a homeless Māori woman, Ariā. The actions of this Māori woman exemplify how Indigenous cultural practices can shape a person’s efforts to retain a positive sense of self and place while homeless. Māori cultural concepts relating to caring, leadership, unity, relationships, spirituality, history and place provide a basis for interpreting Ariā’s actions. This article demonstrates the appropriateness of cultural concepts indigenous to a group for conducting ethnographic research into homelessness within that group.

year: 2011-09