title: Implementation aspects of a new linear regulator topology based on low frequency supercapacitor circulation

authors: Kankanamge, Kosala

abstract: Point of load (POL) powering concepts are used in modern portable products where low dropout regulators (LDO) are mixed with switching regulators. However, LDOs are efficient only when the input to output differential voltage is small. When the input to output differential voltage is large, this efficiency limitation can be overcome by applying a supercapacitor circulation technique at the input side of the LDO. With the commercial LDOs available with output current ratings up to 10A, and, thin profile supercapacitors with DC voltage ratings from 2.3V to 5.5V, this patented technique can be easily configured for common DC-DC converters such as 12 to 5V, 5 to 3.3V and 5 to 1.5V. This novel topology helps increasing the end-to-end efficiency of LDO based linear converters closer to the efficiency benchmarks of modern switch mode power supplies, maintaining the superior output specifications of a linear regulator. Paper provides practical implementation details of different cases discussing the important design aspects, and how this novel topology could assist increasing the end-to-end efficiency of a linear regulator, with a view to get the best out of linear regulator based DC-DC converters.

text: Implementation aspects of a new linear regulator topology based on low frequency supercapacitor circulation Point of load (POL) powering concepts are used in modern portable products where low dropout regulators (LDO) are mixed with switching regulators. However, LDOs are efficient only when the input to output differential voltage is small. When the input to output differential voltage is large, this efficiency limitation can be overcome by applying a supercapacitor circulation technique at the input side of the LDO. With the commercial LDOs available with output current ratings up to 10A, and, thin profile supercapacitors with DC voltage ratings from 2.3V to 5.5V, this patented technique can be easily configured for common DC-DC converters such as 12 to 5V, 5 to 3.3V and 5 to 1.5V. This novel topology helps increasing the end-to-end efficiency of LDO based linear converters closer to the efficiency benchmarks of modern switch mode power supplies, maintaining the superior output specifications of a linear regulator. Paper provides practical implementation details of different cases discussing the important design aspects, and how this novel topology could assist increasing the end-to-end efficiency of a linear regulator, with a view to get the best out of linear regulator based DC-DC converters.

year: 2012

title: Exploration of association rule mining for coding consistency and completeness assessment in inpatient administrative health data.

authors: Peng, Mingkai

subjects: Association rule mining

abstract: OBJECTIVE: Data quality assessment is a challenging facet for research using coded administrative health data. Current assessment approaches are time and resource intensive. We explored whether association rule mining (ARM) can be used to develop rules for assessing data quality. MATERIALS AND METHODS: We extracted 2013 and 2014 records from the hospital discharge abstract database (DAD) for patients between the ages of 55 and 65 from five acute care hospitals in Alberta, Canada. The ARM was conducted using the 2013 DAD to extract rules with support ≥0.0019 and confidence ≥0.5 using the bootstrap technique, and tested in the 2014 DAD. The rules were compared against the method of coding frequency and assessed for their ability to detect error introduced by two kinds of data manipulation: random permutation and random deletion. RESULTS: The association rules generally had clear clinical meanings. Comparing 2014 data to 2013 data (both original), there were 3 rules with a confidence difference >0.1, while coding frequency difference of codes in the right hand of rules was less than 0.004. After random permutation of 50% of codes in the 2014 data, average rule confidence dropped from 0.72 to 0.27 while coding frequency remained unchanged. Rule confidence decreased with the increase of coding deletion, as expected. Rule confidence was more sensitive to code deletion compared to coding frequency, with slope of change ranging from 1.7 to 184.9 with a median of 9.1. CONCLUSION: The ARM is a promising technique to assess data quality. It offers a systematic way to derive coding association rules hidden in data, and potentially provides a sensitive and efficient method of assessing data quality compared to standard methods.

text: Exploration of association rule mining for coding consistency and completeness assessment in inpatient administrative health data. OBJECTIVE: Data quality assessment is a challenging facet for research using coded administrative health data. Current assessment approaches are time and resource intensive. We explored whether association rule mining (ARM) can be used to develop rules for assessing data quality. MATERIALS AND METHODS: We extracted 2013 and 2014 records from the hospital discharge abstract database (DAD) for patients between the ages of 55 and 65 from five acute care hospitals in Alberta, Canada. The ARM was conducted using the 2013 DAD to extract rules with support ≥0.0019 and confidence ≥0.5 using the bootstrap technique, and tested in the 2014 DAD. The rules were compared against the method of coding frequency and assessed for their ability to detect error introduced by two kinds of data manipulation: random permutation and random deletion. RESULTS: The association rules generally had clear clinical meanings. Comparing 2014 data to 2013 data (both original), there were 3 rules with a confidence difference >0.1, while coding frequency difference of codes in the right hand of rules was less than 0.004. After random permutation of 50% of codes in the 2014 data, average rule confidence dropped from 0.72 to 0.27 while coding frequency remained unchanged. Rule confidence decreased with the increase of coding deletion, as expected. Rule confidence was more sensitive to code deletion compared to coding frequency, with slope of change ranging from 1.7 to 184.9 with a median of 9.1. CONCLUSION: The ARM is a promising technique to assess data quality. It offers a systematic way to derive coding association rules hidden in data, and potentially provides a sensitive and efficient method of assessing data quality compared to standard methods.

year: 2018

title: Arts Festival: 'Moonwalking Backwards Into The Future: "Poi E", Music Video and Documentary'

authors: Perrott, Lisa

subjects: Art

abstract: Research presentation - an audiovisual presentation drawing upon my published research (book chapter: 'Moonwalking Backwards Into The Future: "Poi E", Music Video and Documentary'). This presentation presented a Matuaranga Maori perspective of the temporal travels of music video and documentary, framed by the concept of whakapap. This presentation took place as part of a panel of 4 presenters who represented Te Kura Toi at the Arts Festival during the University of Waikato Open Day, 2023. This was an oral presentation, which included projected slides and videos from a PPT presentation. The audience included prospective students, their teachers and family members, community members, and current students and academic staff from the University of Waikato. My presentation was documented and photographed.

text: Arts Festival: 'Moonwalking Backwards Into The Future: "Poi E", Music Video and Documentary' Research presentation - an audiovisual presentation drawing upon my published research (book chapter: 'Moonwalking Backwards Into The Future: "Poi E", Music Video and Documentary'). This presentation presented a Matuaranga Maori perspective of the temporal travels of music video and documentary, framed by the concept of whakapap. This presentation took place as part of a panel of 4 presenters who represented Te Kura Toi at the Arts Festival during the University of Waikato Open Day, 2023. This was an oral presentation, which included projected slides and videos from a PPT presentation. The audience included prospective students, their teachers and family members, community members, and current students and academic staff from the University of Waikato. My presentation was documented and photographed.

year: 2023-05-26