scholarly journals Demographic Projections: User and Producer Experiences of Adopting a Stochastic Approach

2016 ◽  
Vol 32 (4) ◽  
pp. 947-962 ◽  
Author(s):  
Kim Dunstan ◽  
Christopher Ball
Keyword(s):  
New Zealand ◽  
Probabilistic Approach ◽  
Stochastic Approach ◽  
New Approach ◽  
Demographic Projections ◽  
Statistical Agencies

Abstract Statistics New Zealand is one of the few national statistical agencies to have applied a stochastic (probabilistic) approach to official demographic projections. This article discusses the experience and benefits of adopting this new approach, including the perspective of a key user of projections, the New Zealand Treasury. Our experience is that the change is less difficult to make than might be expected. Uncertainty in the different projection inputs (components) can be modelled simply or with more complexity, and progressively applied to different projection types. This means that not all the different demographic projections an agency produces need to adopt a stochastic approach simultaneously. At the same time, users of the projections are keen to better understand the relative certainty and uncertainty of projected outcomes, given the important uses of projections.

Error Analysis of Cam-Follower Systems: A Probabilistic Approach

1984 ◽  
Vol 198 (3) ◽  
pp. 155-162 ◽  
Author(s):  
S S Rao
Keyword(s):  
Error Analysis ◽  
Probabilistic Approach ◽  
Random Variables ◽  
Stochastic Approach ◽  
Geometrical Parameters ◽  
Manufacturing Costs ◽  
Actual Output ◽  
Analysis And Synthesis ◽  
Cam Follower ◽  
Synthesis Procedure

The actual output kinematic characteristics of a cam-follower system will be different from the theoretical (desired) ones due to errors in manufacture and assembly. A method of evaluating the mechanical error in the kinematic response of cam-follower systems is presented using a stochastic approach. The tolerances on cam profiles and other geometrical parameters are treated as random variables that influence the mechanical error. The equations necessary for the mechanical error analysis of a planar cam-follower system (disc cam with translating roller follower) are derived. The equations for a spatial cam-follower system (globoidal cam with oscillating cylindrical follower) are also given at the end. An optimal synthesis procedure is outlined for the allocation of tolerances so as to minimize the manufacturing costs while satisfying a constraint on the maximum mechanical error in the kinematic response of cam-follower systems. The application of analysis and synthesis procedure is demonstrated with reference to a disc cam with translating roller follower.

Highly localized upper mantle deformation during plate boundary initiation near the Alpine fault, New Zealand

Geology ◽  
2021 ◽  
Author(s):  
Steven Kidder ◽  
David J. Prior ◽  
James M. Scott ◽  
Hamid Soleymani ◽  
Yilun Shao
Keyword(s):  
New Zealand ◽  
Upper Mantle ◽  
Plate Boundary ◽  
New Approach ◽  
Fine Grained ◽  
Alpine Fault ◽  
Narrow Width ◽  
Plate Boundary Deformation ◽  
Boundary Deformation ◽  
Total Shear

Peridotite xenoliths entrained in magmas near the Alpine fault (New Zealand) provide the first direct evidence of deformation associated with the propagation of the Australian-Pacific plate boundary through the region at ca. 25–20 Ma. Two of 11 sampled xenolith localities contain fine-grained (40–150 mm) rocks, indicating that deformation in the upper mantle was focused in highly sheared zones. To constrain the nature and conditions of deformation, we combine a flow law with a model linking recrystallized fraction to strain. Temperatures calculated from this new approach (625–970 °C) indicate that the observed deformation occurred at depths of 25–50 km. Calculated shear strains were between 1 and 100, which, given known plate offset rates (10–20 mm/yr) and an estimated interval during which deformation likely occurred (<1.8 m.y.), translate to a total shear zone width in the range 0.2–32 km. This narrow width and the position of mylonite-bearing localities amid mylonite-free sites suggest that early plate boundary deformation was distributed across at least ~60 km but localized in multiple fault strands. Such upper mantle deformation is best described by relatively rigid, plate-like domains separated by rapidly formed, narrow mylonite zones.

Instantaneous spatio-temporal rate of spread of fast spreading wildfires - a new approach from visible and thermal image processing

2021 ◽  
Author(s):  
Benjamin Schumacher ◽  
Katharine Melnik ◽  
Marwan Katurji ◽  
Veronica Clifford ◽  
Jiawei Zhang ◽  
...  
Keyword(s):  
Remote Sensing ◽  
New Zealand ◽  
Stand Structure ◽  
Fire Severity ◽  
Thermal Infrared ◽  
Fire Spread ◽  
New Approach ◽  
Rate Of Spread ◽  
Fast Spreading ◽  
Fire Experiments

<p>The rate of spread (ROS) of wildfires is an important parameter for understanding fire-atmospheric interactions and developing fire-spread models, but it is also vital for firefighting operations to ensure the safety of firefighters (Plucinski 2017, Stow 2019). Spatial ROS observations are usually carried out by using visible and thermal satellite imagery of wildfires estimating the ROS on a time scale of hours to days for large fires (>100 ha) or repeated passing with an airborne thermal infrared imager for higher spatial and temporal resolution (Viedma et al. 2015, Stow 2014). For fire experiments in highly controlled conditions like laboratory fires or during light fuel prescribed burns, ROS estimation usually involves lag-correlation of temperature point measurements (Finney 2010, Johnston 2018). However, these methodologies are not applicable to fast-spreading grass or bush fires because of their temporal and spatial limitations. Instantaneous spatial ROS of these fires is needed to understand rapid changes in connection with the three major drivers of the fire: fuel, topography and atmospheric forcings.</p><p>We are presenting a new approach towards a spatial ROS product which includes newly developed image tracking methods based on thermal and visible imagery collected from unmanned aerial vehicles to estimate instantaneous, spatial ROS of fast spreading grass or bush fires. These techniques were developed using imagery from prescribed wheat-stubble burns carried out in Darfield, New Zealand in March 2018 (Finney 2018). Results show that both the visible and thermal tracking techniques produce similar mean ROS; however they differ in limitations and advantages. The visible-spectrum tracking method clearly identifies the flaming zone and provides accurate ROS measurements especially at the fire front. The thermal tracking technique is superior when resolving dynamics and ROS within the flaming zone because it resolves smaller scale structures within the imagery.</p><p> </p><p>References:</p><p>Finney, M. et al. 2010: An Examination of Fire Spread Thresholds in Discontinuous Fuel Beds.” International Journal of Wildland Fire, 163–170.</p><p>Finney, M. et al. 2018: New Zealand prescribed fire experiments to test convective heat transfer in wildland fires. In Advances in Forest Fire Research, Imprensa da Universidade de Coimbra: Coimbra, 2018.</p><p>Johnston, J. M., et al. 2018:  Flame-Front Rate of Spread Estimates for Moderate Scale Experimental Fires are Strongly Influenced by Measurement Approach. Fire 1: 16–17</p><p>Plucinski M., et al. 2017: Improving the reliability and utility of operational bushfire behaviour predictions in Australian vegetation. Environmental Modelling & Software 91, 1-12.</p><p>Stow, D., et al. 2014: Measuring Fire Spread Rates from Repeat PassAirborne Thermal Infrared Imagery. Remote Sensing Letters 5: 803–881.</p><p>Stow, D., et al. 2019: Assessing uncertainty and demonstrating potentialfor estimating fire rate of spread at landscape scales based on time sequential airbornethermal infrared imaging, International Journal of Remote Sensing, 40:13, 4876-4897</p><p>Viedma, O., et al. 2015:  Fire Severity in a Large Fire in a Pinus Pinaster Forest Is Highly Predictable from Burning Conditions, Stand Structure, and Topography. Ecosystems18: 237–250.</p>

Shocks vs. Impulse-Propagation Model of Economic Dynamics

2021 ◽  
pp. 1-28
Keyword(s):  
Business Cycle ◽  
Wave Theory ◽  
Stochastic Approach ◽  
Propagation Model ◽  
Self Organization ◽  
Scientific Contribution ◽  
Economic Dynamics ◽  
New Approach ◽  
Self Development ◽  
Random Fluctuations

Ragnar Frisch, the Nobel prizer in economics, drew attention to two phenomena: propagation problems and impulse problems in dynamic economics. His deep scientific contribution relates to the interpretation of business cycle transformed under the influence of impulses (shocks). But some terminological misunderstandings arose. One of them forced the authors to focus on the phenomenon of systems' self-movement: their self-organization in statics and their self-development in dynamics. Another one relates to exogenous nature of impulses (shocks) that forced the authors to prove the endogenous embeddedness of shocks into the mechanisms of dialectical laws implementation. Eugen Slutsky demonstrated the stochastic approach as to random fluctuations as a source of cyclical processes in the economy. The confusion in the concepts of cycles and waves predetermines the need to create a wave theory of systemic self-organization (Chapter 2). Modern shocks theory develops a new approach which makes it possible to eliminate misconceptions of past theories.

The Principles of Equity & Trusts

2018 ◽  
Author(s):  
Graham Virgo
Keyword(s):  
New Zealand ◽  
Common Law ◽  
Fiduciary Duty ◽  
Final Part ◽  
New Approach ◽  
The Subject ◽  
The Law ◽  
Contemporary Context

The Principles of Equity & Trusts offers a new approach to this dynamic area of law. This book examines the law of Equity and Trusts in its contemporary context, offering a critical and insightful commentary on the law, its application, and development. The text communicates both Equity and trust doctrine and also theory and reflects the modern understanding of the subject, as propounded both by the judiciary and commentators in England and other Common Law jurisdictions, notably Australia, Canada, New Zealand, and Singapore. The book consists of nine parts. Part I considers the history and contemporary relevance of Equity. Part II is about the express trust. Part III considers purpose trusts. Part IV then examines implied trusts. Part V is about beneficiaries. Part VI examines trustees’ powers and duties. Part VII examines variations of trusts. Part VIII is about breach of trust and fiduciary duty and the personal and proprietary remedies available for such breach. The final part examines other equitable remedies.

Effect of Notch Location on the Stress Concentration and Reliability of Notched Composite Laminates Based on a Probabilistic Approach

2007 ◽  
Author(s):  
R. Ganesan ◽  
A. K. Arumugam
Keyword(s):  
Stress Concentration ◽  
Stress Distribution ◽  
Composite Laminates ◽  
Probabilistic Approach ◽  
Stochastic Approach ◽  
Strength Properties ◽  
Practical Reasons ◽  
Commercial Aircraft ◽  
Reinforced Plastics ◽  
Reliability Based Design

Composite materials and laminates are being widely used in aerospace and automotive industries due to their less weight to stiffness ratio. Especially the use of composite laminates, made up of Carbon or Graphite Fiber Reinforced Plastics (CFRP/GFRP), in military and commercial aircraft structures has progressed steadily over the past few decades. Drilling holes and making cutouts in these laminates are unavoidable for practical reasons. These holes (or) cutouts introduces stress concentration near the hole (or) cutout edge and reduces the load-bearing capacity of the structure. Cutouts are made at the edges of composite laminates for practical purposes, which is capable of reducing the delamination effect in notched laminates. The stress distribution in notched composite laminates can vary according to the location of the notch in the laminate, which leads to the variation in strength and reliability values of notched laminates. The objective of the present work is to study the effect of notch location on the stress concentration and reliability of notched composite laminates. Composite laminate displays significant variation in material and strength properties and the stress distribution in the laminate becomes stochastic in nature. Thus the notched laminates were analyzed using a stochastic approach and designed based on a reliability-based design approach.

scholarly journals Using Bayesian Models To Forecast International Arrivals And Departures By Age, Sex, And Region In New Zealand

2015 ◽  
Author(s):  
John Bryant ◽  
Kirsten Nissen
Keyword(s):  
New Zealand ◽  
Hierarchical Models ◽  
Statistical Approach ◽  
Small Population ◽  
Population Projections ◽  
Deterministic Approach ◽  
Bayesian Hierarchical ◽  
Migration Rates ◽  
Statistical Agencies ◽  
Measure Of Uncertainty

Statistics New Zealand prepares regular population projections at the subnational level. Like other statistical agencies, Statistics NZ currently uses a deterministic approach to subnational projections. However, we are currently developing an alternative, more statistical, approach. In this paper, we describe two Bayesian hierarchical models for estimating and forecasting international in-migration and out-migration rates, disaggregated by age, sex, and territorial authority. The model uses international arrivals and departures data for 1991-2013, and produces forecasts for 2014-2039. Special attention is given to the ability of the model to estimate migration rates for small population domains. The modelled approach provides a coherent and integrated measure of uncertainty at the detailed demographic level. Examples of estimated and forecasted migration rates are presented. We conclude with a discussion of the challenges and limitations of the data and model, and directions for future developments.

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