title: Innovative cold-formed steel nested tapered box section portal frames with bolted-side plate joints

authors: Paul, Bikram

abstract: Nested tapered box (NTB) portal frames made entirely of cold-formed steel (CFS) are widely used in New Zealand. Shahmohammadi (2019) recently described a full-scale test of such a system. The tested frame had a span of 18.16 meters and a height to the eaves of 4.27 meters. The joints of this NTB portal frame were rigid, constructed with bolted end plates. However, bolted end plate joints can be expensive due to the full penetration butt weld. This thesis proposes an alternative jointing system that uses bolted-side plates. The numerical work conducted in this study yields the following findings:
•	A shell finite element (FE) model was developed and validated using previously conducted full-scale portal frame tests. This validated model was then employed to compare the performance of bolted-side plate joints with bolted end-plate joints. The analysis revealed that a portal frame with 10 mm thick bolted side plates could sustain the same load as an NTB portal frame with bolted end-plate joints. Increasing the thickness of the bolted-side plates from 10 mm to 16 mm resulted in a 20% increase in load-carrying capacity. This improvement was due to the confinement effect provided by the side plates, which reduced the slenderness ratio near the eaves joint. However, the NTB portal frame with bolted-side plates exhibited greater apex displacement compared to the frame with bolted end-plate joints. 
•	FE models were developed for both the eaves and apex joints of the NTB portal frame.  A parametric study was then carried out involving 1,000 FE models. Using FE models, design equations are proposed for the moment capacities of the eaves and apex bolted side plates, accounting for both opening and closing moments under partial restraint.
•	A parametric study was conducted using the developed design method on eight models, considering a range of spans from 25m to 40m and eaves heights from 5.5m to 6.25m, with a consistent frame spacing of 7.5m. The results showed that portal frames with bolted-side plates can carry on average 7% more load compared to those with bolted end plate joints.
•	A methodology was presented to predict the load-carrying capacity of portal frames with back-to-back channel sections. It was shown that the predicted vertical loads from the proposed approach were, on average, within 1% (on an average) of the FEA results for portal frames. The same approach was applied to NTB portal frames through worked examples in Appendix B and C, demonstrating good accuracy.

text: Innovative cold-formed steel nested tapered box section portal frames with bolted-side plate joints Nested tapered box (NTB) portal frames made entirely of cold-formed steel (CFS) are widely used in New Zealand. Shahmohammadi (2019) recently described a full-scale test of such a system. The tested frame had a span of 18.16 meters and a height to the eaves of 4.27 meters. The joints of this NTB portal frame were rigid, constructed with bolted end plates. However, bolted end plate joints can be expensive due to the full penetration butt weld. This thesis proposes an alternative jointing system that uses bolted-side plates. The numerical work conducted in this study yields the following findings:
•	A shell finite element (FE) model was developed and validated using previously conducted full-scale portal frame tests. This validated model was then employed to compare the performance of bolted-side plate joints with bolted end-plate joints. The analysis revealed that a portal frame with 10 mm thick bolted side plates could sustain the same load as an NTB portal frame with bolted end-plate joints. Increasing the thickness of the bolted-side plates from 10 mm to 16 mm resulted in a 20% increase in load-carrying capacity. This improvement was due to the confinement effect provided by the side plates, which reduced the slenderness ratio near the eaves joint. However, the NTB portal frame with bolted-side plates exhibited greater apex displacement compared to the frame with bolted end-plate joints. 
•	FE models were developed for both the eaves and apex joints of the NTB portal frame.  A parametric study was then carried out involving 1,000 FE models. Using FE models, design equations are proposed for the moment capacities of the eaves and apex bolted side plates, accounting for both opening and closing moments under partial restraint.
•	A parametric study was conducted using the developed design method on eight models, considering a range of spans from 25m to 40m and eaves heights from 5.5m to 6.25m, with a consistent frame spacing of 7.5m. The results showed that portal frames with bolted-side plates can carry on average 7% more load compared to those with bolted end plate joints.
•	A methodology was presented to predict the load-carrying capacity of portal frames with back-to-back channel sections. It was shown that the predicted vertical loads from the proposed approach were, on average, within 1% (on an average) of the FEA results for portal frames. The same approach was applied to NTB portal frames through worked examples in Appendix B and C, demonstrating good accuracy.

year: 2025

title: Surface projection for mixed pixel restoration

authors: Larkins, Robert L.

subjects: range imaging

abstract: Amplitude modulated full-field range-imagers are measurement devices that determine the range to an object simultaneously for each pixel in the scene, but due to the nature of this operation, they commonly suffer from the significant problem of mixed pixels. Once mixed pixels are identified a common procedure is to remove them from the scene; this solution is not ideal as the captured point cloud may become damaged. This paper introduces an alternative approach, in which mixed pixels are projected onto the surface that they should belong. This is achieved by breaking the area around an identified mixed pixel into two classes. A parametric surface is then fitted to the class closest to the mixed pixel, with this mixed pixel then being project onto this surface. The restoration procedure was tested using twelve simulated scenes designed to determine its accuracy and robustness. For these simulated scenes, 93% of the mixed pixels were restored to the surface to which they belong. This mixed pixel restoration process is shown to be accurate and robust for both simulated and real world scenes, thus provides a reliable alternative to removing mixed pixels that can be easily adapted to any mixed pixel detection algorithm.

text: Surface projection for mixed pixel restoration Amplitude modulated full-field range-imagers are measurement devices that determine the range to an object simultaneously for each pixel in the scene, but due to the nature of this operation, they commonly suffer from the significant problem of mixed pixels. Once mixed pixels are identified a common procedure is to remove them from the scene; this solution is not ideal as the captured point cloud may become damaged. This paper introduces an alternative approach, in which mixed pixels are projected onto the surface that they should belong. This is achieved by breaking the area around an identified mixed pixel into two classes. A parametric surface is then fitted to the class closest to the mixed pixel, with this mixed pixel then being project onto this surface. The restoration procedure was tested using twelve simulated scenes designed to determine its accuracy and robustness. For these simulated scenes, 93% of the mixed pixels were restored to the surface to which they belong. This mixed pixel restoration process is shown to be accurate and robust for both simulated and real world scenes, thus provides a reliable alternative to removing mixed pixels that can be easily adapted to any mixed pixel detection algorithm.

year: 2009

title: Rising demand for health care: The sustainability of community general practice in the Waikato

authors: Amey, Janet Heather

subjects: General practice

abstract: Community general practice is the cornerstone of New Zealand’s health system, providing first contact health care, care coordination and acting as gatekeeper to expensive hospital services. An ageing population now brings increasing demand for the care provided in general practice, with chronic conditions a major contributing factor. This rising demand, alongside limited workforce capacity will seriously test general practice sustainability. 

These evolving and multifaceted challenges are within the context of long-standing health access and outcome inequalities, particularly for Māori (and more recently the Pacific population) compared with Pākehā. The pursuit of equity is inherent in all health sector strategies, but any meaningful improvement will necessitate wide-ranging reform of current planning, funding and service delivery pathways across traditional sector boundaries.

The sustainability of general practice is about the sustainability and efficiency of the entire health system. To better measure the contribution of general practice care to the system, and improve demand projections, an expanded service use measure was developed, combining services of a general practice nature from Emergency Department and Accident & Medical settings with services delivered in community general practice.

Drawing on approaches from demography, epidemiology and health services research, linked demographic and health administrative data were used to undertake a retrospective, observational study of service use for 235,666 people enrolled with the Pinnacle Midlands Health Network in 2013/14. Using the new expanded measure, service use levels at a locality level were established by age, gender, ethnic group, chronic condition status, practice funding model, high needs status, income and geography of residence.

Significant variation was found in annual average consults (1.0 to 13.4 consults in 2013/14). Statistical analysis identified age, chronic conditions and gender as the key demand drivers responsible for such variation, with regional level results masking significant spatial variation. Where the cost of care was lower, people used a higher level of services in the enrolled practice setting and a lower level outside of it, suggesting the importance of affordable care. Māori and Pacific used significantly fewer services than Pākehā although there was substantial sub-regional variation. Using the expanded measure, the vast majority of care was delivered in the enrolled setting, including for those with chronic conditions.

Demand projections, based on the expanded measure of general practice, out to 2038 show the uneven geography of future demand due to disordered cohort flows and sub-regional population contexts. Overall, demand for services is projected to rise by 34 per cent to almost two million consults across the Waikato District Health Board catchment, with this driven predominantly by services for those aged 65+ years (or 45+ years in Hamilton City, Waikato and Waipa Districts).

Models of care are being transformed as general practices and Primary Health Organisations look to the future. Reorganisation of work roles, improved use of health information and use of emerging health technologies will be required to re-configure general practice in preparation for an ageing future, and to eliminate recalcitrant health inequalities. Real and inclusive collaboration across traditional system boundaries is perhaps the greatest challenge to general practice sustainability.

text: Rising demand for health care: The sustainability of community general practice in the Waikato Community general practice is the cornerstone of New Zealand’s health system, providing first contact health care, care coordination and acting as gatekeeper to expensive hospital services. An ageing population now brings increasing demand for the care provided in general practice, with chronic conditions a major contributing factor. This rising demand, alongside limited workforce capacity will seriously test general practice sustainability. 

These evolving and multifaceted challenges are within the context of long-standing health access and outcome inequalities, particularly for Māori (and more recently the Pacific population) compared with Pākehā. The pursuit of equity is inherent in all health sector strategies, but any meaningful improvement will necessitate wide-ranging reform of current planning, funding and service delivery pathways across traditional sector boundaries.

The sustainability of general practice is about the sustainability and efficiency of the entire health system. To better measure the contribution of general practice care to the system, and improve demand projections, an expanded service use measure was developed, combining services of a general practice nature from Emergency Department and Accident & Medical settings with services delivered in community general practice.

Drawing on approaches from demography, epidemiology and health services research, linked demographic and health administrative data were used to undertake a retrospective, observational study of service use for 235,666 people enrolled with the Pinnacle Midlands Health Network in 2013/14. Using the new expanded measure, service use levels at a locality level were established by age, gender, ethnic group, chronic condition status, practice funding model, high needs status, income and geography of residence.

Significant variation was found in annual average consults (1.0 to 13.4 consults in 2013/14). Statistical analysis identified age, chronic conditions and gender as the key demand drivers responsible for such variation, with regional level results masking significant spatial variation. Where the cost of care was lower, people used a higher level of services in the enrolled practice setting and a lower level outside of it, suggesting the importance of affordable care. Māori and Pacific used significantly fewer services than Pākehā although there was substantial sub-regional variation. Using the expanded measure, the vast majority of care was delivered in the enrolled setting, including for those with chronic conditions.

Demand projections, based on the expanded measure of general practice, out to 2038 show the uneven geography of future demand due to disordered cohort flows and sub-regional population contexts. Overall, demand for services is projected to rise by 34 per cent to almost two million consults across the Waikato District Health Board catchment, with this driven predominantly by services for those aged 65+ years (or 45+ years in Hamilton City, Waikato and Waipa Districts).

Models of care are being transformed as general practices and Primary Health Organisations look to the future. Reorganisation of work roles, improved use of health information and use of emerging health technologies will be required to re-configure general practice in preparation for an ageing future, and to eliminate recalcitrant health inequalities. Real and inclusive collaboration across traditional system boundaries is perhaps the greatest challenge to general practice sustainability.

year: 2018