scholarly journals A framework for modeling clustering in natural hazard catastrophe risk management and the implications for re/insurance loss perspectives

2014 ◽  
Vol 2 (8) ◽  
pp. 5247-5285
Author(s):  
S. Khare ◽  
A. Bonazzi ◽  
C. Mitas ◽  
S. Jewson
Keyword(s):  
Large Scale ◽  
Natural Hazard ◽  
Simulation Models ◽  
Mathematical Framework ◽  
Event Correlation ◽  
Poisson Mixtures ◽  
Hazard Risk ◽  
Starting Point ◽  
Catastrophe Risk Management ◽  
The Impact

Abstract. In this paper, we present a novel framework for modelling clustering in natural hazard risk models. The framework we present is founded on physical principles where large-scale oscillations in the physical system is the source of non-Poissonian (clustered) frequency behaviour. We focus on a particular mathematical implementation of the "Super-Cluster" methodology that we introduce. This mathematical framework has a number of advantages including tunability to the problem at hand, as well as the ability to model cross-event correlation. Using European windstorm data as an example, we provide evidence that historical data show strong evidence of clustering. We then develop Poisson and clustered simulation models for the data, demonstrating clearly the superiority of the clustered model which we have implemented using the Poisson-Mixtures approach. We then discuss the implications of including clustering in models of prices on catXL contracts, one of the most commonly used mechanisms for transferring risk between primary insurers and reinsurers. This paper provides a number of new insights into the impact clustering has on modelled catXL contract prices. The simple model presented in this paper provides an insightful starting point for practicioners of natural hazard risk modelling.

scholarly journals Modelling clustering of natural hazard phenomena and the effect on re/insurance loss perspectives

2015 ◽  
Vol 15 (6) ◽  
pp. 1357-1370 ◽  
Author(s):  
S. Khare ◽  
A. Bonazzi ◽  
C. Mitas ◽  
S. Jewson
Keyword(s):  
Natural Hazard ◽  
Simulation Models ◽  
Historical Event ◽  
Event Data ◽  
Event Correlation ◽  
Poisson Mixtures ◽  
Poisson Models ◽  
Starting Point ◽  
High Degree ◽  
The Impact

Abstract. In this paper, we present a conceptual framework for modelling clustered natural hazards that makes use of historical event data as a starting point. We review a methodology for modelling clustered natural hazard processes called Poisson mixtures. This methodology is suited to the application we have in mind as it naturally models processes that yield cross-event correlation (unlike homogeneous Poisson models), has a high degree of tunability to the problem at hand and is analytically tractable. Using European windstorm data as an example, we provide evidence that the historical data show strong evidence of clustering. We then develop Poisson and Clustered simulation models for the data, demonstrating clearly the superiority of the Clustered model which we have implemented using the Poisson mixture approach. We then discuss the implications of including clustering in models of prices of catXL contracts, one of the most commonly used mechanisms for transferring risk between primary insurers and reinsurers. This paper provides a number of unique insights into the impact clustering has on modelled catXL contract prices. The simple modelling example in this paper provides a clear and insightful starting point for practitioners tackling more complex natural hazard risk problems.

scholarly journals Measuring and assessing the impact of using volunteers in UK libraries: issues and methods

2014 ◽  
Vol 15 (3) ◽  
pp. 112-121 ◽  
Author(s):  
Judith Broady-Preston
Keyword(s):  
Systematic Review ◽  
Large Scale ◽  
Third Sector ◽  
Professional Staff ◽  
Research Centre ◽  
Content Type ◽  
Qualitative Approaches ◽  
Starting Point ◽  
Third Sector Organisations ◽  
The Impact

Purpose – The purpose of this paper is to examine a range of issues and methods in relation to measuring the impact of volunteer labour on the design and delivery of all types of library services. With the increasing use of volunteers to deliver library and information services in all sectors, managers need to assess their effectiveness and evaluate the impact of their use in relation to operational service design and delivery, and on the development of the profession and professional practice as a whole. Presented here is an initial scoping study, outlining a range of issues, methods and challenges for more detailed future investigation. Design/methodology/approach – A number of methodological challenges and perspectives are identifiable. Contemporary libraries exhibit increasing similarities with Third Sector organisations, namely a complex stakeholder community, and increasing use of volunteers to supplement or replace services delivered by professional staff. Therefore, a starting point for the research is a systematic review and analysis of the methodologies developed by the Third Sector Research Centre, and those studies in the ESRC contemporary Developing Impact Evaluation strand. As a rich picture is required, both quantitative and qualitative approaches are necessary, with the overall study adopting a mixed methods approach. Findings – This paper reports the findings of the preliminary documentary analysis, literature review and scoping aspects of a large-scale study. Originality/value – Research undertaken to date (June 2014) has failed to identify any published systematic review and examination of these issues.

Influence of Oriented Perforation Design on Refracture Reorientation: Simulation and Experiment

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Minhui Qi ◽  
Mingzhong Li ◽  
Tiankui Guo ◽  
Chunting Liu ◽  
Song Gao ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Large Scale ◽  
Simulation Models ◽  
Fracture Initiation ◽  
Simulation Method ◽  
Induced Stress ◽  
Study Results ◽  
Simulation Results ◽  
Fracturing Experiments ◽  
The Impact

The oriented perforating is the essential technique to guide the refracture reorientation, but the influence of the oriented perforation design on the refracture steering radius is still unclear. In this paper, the factors influencing the refracture reorientation were studied by simulation models and experiments. The effects of initial fracture, well production, and perforations on the refracture initiation and propagation were analyzed. Three-dimensional finite element models were conducted to quantify the impact of perforation depth, density, and azimuth on the refracture. The large-scale three-axis hydraulic fracturing experiments guided by oriented perforations were also carried out to verify the fracture initiation position and propagation pattern of the simulation results. The research results showed that perforations change the near-wellbore induced stress distribution, thus changing the steering radius of the refracture. According to the simulation results, the oriented perforation design has a significant influence on the perforation guidance effect and refracture characteristics. Five hydraulic fracturing experiments proved the influence of perforating parameters on fracture initiation and morphology, which have a right consistency between the simulation results. This paper presents a numerical simulation method for evaluating the influence of the refracture reorientation characteristics under the consideration of multiple prerefracturing induced-stress and put forward the oriented perforation field design suggestions according to the study results.

Arable Land as Commons

2006 ◽  
Vol 30 (3) ◽  
pp. 431-461
Author(s):  
Philip C. Brown
Keyword(s):  
Geographic Information Systems ◽  
Great Risk ◽  
Natural Hazard ◽  
Arable Land ◽  
Flood Hazards ◽  
Land Redistribution ◽  
Hazard Risk ◽  
Village Studies ◽  
The Impact

The origins and role of corporate landholding and land redistribution practices over arable land in seventeenth- to nineteenth-century Japan have posed a quandary for scholars. The most common forms are widely seen as means to spread the impact of flooding among villagers in districts that are considered to be at great risk from flood hazards. Such conclusions are often based on individual village studies. In contrast, this study takes a regional approach and tests the validity of this relationship using geographic information systems technology experimentally. This experiment reveals a variety of anomalies that, taken together, suggest that any link between natural hazard risk and the presence or absence of redistribution practices is more subtle than typical explanations assert.

scholarly journals Effects of Aqua-Dispersing Nano-Binder on Clay Conductivity at Different Temperatures

2019 ◽  
Vol 11 (18) ◽  
pp. 4859
Author(s):  
Cuiying Zhou ◽  
Xingxing Ge ◽  
Wei Huang ◽  
Dexian Li ◽  
Zhen Liu
Keyword(s):  
Ecological Restoration ◽  
Soil Amendment ◽  
Large Scale ◽  
Soil Amendments ◽  
Quantitative Relationship ◽  
Silty Clay ◽  
Research Subjects ◽  
Nutrient Storage ◽  
Starting Point ◽  
The Impact

Soil nutrients are the basis of ecological remediation. Soil amendments can form a reticular membrane structure on the soil surface to increase nutrient storage and alleviate nutrient imbalances, and are affected by the environmental temperature. At present, the qualitative evaluation of the effect of soil amendment is mainly based on vegetative growth. However, with the increasing use of soil amendments, how to conveniently and quantitatively evaluate the impact of soil amendments on ecological restoration under different temperature conditions from the perspective of soil urgently needs to be solved. Therefore, a new soil amendment named aqua-dispersing nano-binder (ADNB) and silty clay that is commonly used for ecological restoration in South China were used as research subjects, and the important soil nutrient storage capacity—soil conductivity index—was used as the starting point to find solutions to the above problems. We independently developed a multifunctional instrument to measure the soil amendment concentration. Clay conductivity measurements were used by adding different concentrations of ADNB within the range of 0 to 50 °C, and the mechanism by which temperature and ADNB affect the conductivity of clay was revealed. In addition, the quantitative relationship between the clay conductivity, ambient temperature and concentration of ADNB was elucidated. According to the growth conditions of melinis minutiflora and pigeon pea under different concentrations of ADNB, the optimal ADNB concentration needed to improve ecological restoration was obtained, which provided a new way to evaluate the effects of the large-scale use of soil modifiers on ecological restoration.

The Next ‘Spring’ is Certain to Come – and Certain to be Missed

2014 ◽  
Vol 6 (4) ◽  
pp. 382-406 ◽  
Author(s):  
Witold Mucha
Keyword(s):  
Large Scale ◽  
Task Force ◽  
Authoritarian Regimes ◽  
The Political ◽  
International Crisis ◽  
Starting Point ◽  
To Come ◽  
International Crisis Group ◽  
The Arab Spring ◽  
The Impact

The Arab Spring took policymakers and academics by surprise. The starting point, the scope, nor the impact had been seen coming. This was primarily because of academics’ irrevocable belief in the stabilising power of authoritarian regimes. In light of this failing, the article will critically discuss the production of crisis knowledge on the basis of four major early warning tools. These are World Bank’s greed/grievance model, the predictive model by the Political Instability Task Force, the risk and capacity approach applied by the Failed States Index, and the International Crisis Group. The article will add to the debate in two ways. First, the analysis will show that prevention research can be biased in ways that crucially influence policymakers’ assessment of states at risk. Second, the article will argue in favour of a complementary perspective that includes the analysis of conflicts that do not erupt into large-scale violence against all odds (so-called ‘negative cases’).

Open-plan office post-occupancy evaluation: inquiring Algerian gender specificity

Facilities ◽  
2018 ◽  
Vol 36 (11/12) ◽  
pp. 546-570
Author(s):  
Abdelkrim Benammar ◽  
Karima Anouche ◽  
Hasnia Lesgaa ◽  
Yamina Hamza Cherif
Keyword(s):  
Public Space ◽  
Large Scale ◽  
Working Environment ◽  
Space Environment ◽  
Future Research ◽  
Content Type ◽  
Post Occupancy Evaluation ◽  
Starting Point ◽  
Open Plan ◽  
The Impact

PurposeThis paper aims to examine the impact of an open-plan office (OPO) space organisation on a user’s attitude in the Algerian context; more specifically, it investigates gender differences in the occupants’ perception of such working environment. It, principally, aims to explore the employees’ reaction towards OPO and sees how much such local office type complies with indoor environment quality (IEQ) and psychological comfort.Design/methodology/approachThe theoretical framework of the study is mainly related to environmental psychology referring to the interaction between users and their environment. Post-occupancy evaluation was carried out using exploratory study and questionnaires, followed by statistical analyses. It was performed on a large-scale sample of employees (296 employees) working in recently built OPO situated in Oran (Algeria).FindingsFundamentally, women appear to show more concern regarding comfort. They do not show much reluctance to be mixed with men in a large office space as opposed to more conservative reaction towards mixing up in outdoor public space environment. As for environmental factors (IEQ), indicators have shown the inadequacy of most buildings in terms of thermal, light or noise comfort. The study has also revealed that a majority of users recognise the professional advantages of the OPO, although it is suggested that their preferred type would be the individual office.Originality/valueThe paper provides a concise starting point for future research interested in developing Algerian context OPO design in terms of both indoor environmental and psychological comfort.

An approach towards addressing meteorological factors for extreme event impacts

2020 ◽  
Author(s):  
Uwe Ulbrich ◽  
Jens Grieger
Keyword(s):  
Extreme Events ◽  
Large Scale ◽  
Climate Models ◽  
Extreme Event ◽  
Heat Waves ◽  
Meteorological Factors ◽  
Ministry Of Education ◽  
Starting Point ◽  
Compound Events ◽  
The Impact

<p>The ClimXtreme program funded by the German Ministry of Education and Research is designed to address Physics and Processes, Statistics, and Impacts of meteorological extreme events, considering both the past period covered by instrumental measurements, and future climate scenarios. In its branch on impacts, the impact of hazards in Europe (convective events, severe precipitation, heat waves and droughts, and large scale storms) shall be considered in order to identify the underlying relevant weather situations and the antecedent meteorological factors. The specific characteristics of the extreme events shall also be explored. Aiming at a better understanding of the impacts of the extremes, investigations shall go beyond quantification of the local severity of a hazard. The assumption is that there is also an influence of weather and climate on exposure and vulnerability. These factors for the occurrence and the magnitude of damaging impacts  thus depend on local climatology, the occurrence of specific weather sequences augmenting vulnerability, or the occurrence of specific combinations of factors which individually needn’t be extreme (compound events).  One starting point are thus already existing impact models, which do not take (all of) these factors into account. Results from numerical climate models will be used to estimate the future change of risks under climate change.</p>

Armed groups and intra-state conflicts: the dawn of a new era?

2011 ◽  
Vol 93 (882) ◽  
pp. 287-310 ◽  
Author(s):  
Arnaud Blin
Keyword(s):  
New York ◽  
Soviet Union ◽  
Large Scale ◽  
Current Trend ◽  
Armed Conflicts ◽  
Environmental Damage ◽  
General Context ◽  
Armed Groups ◽  
Starting Point ◽  
The Impact

AbstractHave the various profound changes that have affected the world, and particularly its geostrategic dimensions, since the end of the Cold War radically altered the nature of conflicts? Twenty years after the collapse of the Soviet Union and ten years after the destruction of the twin towers in New York, there is an apparent degree of continuity in the resilience of former centres of unresolved conflicts and of armed groups involved in them. Nonetheless, whereas most armed conflicts can today be classified as ‘intra-state’, the general context has changed to the extent that reference is now made to the phenomenon of ‘new wars’. Increasingly inacceptable economic and political imbalances along with globalization, environmental damage and its consequences or the emergence of large-scale conflicts triggered by organized crime are some of the perils already affecting the nature of today's conflicts or potentially defining those of the future. As the period dominated by jihadist groups with a universalist vocation possibly draws to an end, the current trend seems to be towards a new generation of guerrilla fighters who stand to benefit, in particular, from the erosion of the nation-state and from geopolitical convulsions arising from the post-colonial legacy as the starting point for intensely zealous and violent long-term ventures. The impact of globalization could cause a flare-up of some existing conflicts that are currently limited in scope while the international community struggles to redefine other rules and to adapt them to the new dialectic of war and peace.

Optimizing electronic standard cell libraries for variability tolerance through the nano-CMOS grid

2010 ◽  
Vol 368 (1925) ◽  
pp. 3967-3981 ◽  
Author(s):  
James Alfred Walker ◽  
Richard Sinnott ◽  
Gordon Stewart ◽  
James A. Hilder ◽  
Andy M. Tyrrell
Keyword(s):  
High Speed ◽  
High Performance ◽  
Large Scale ◽  
Circuit Simulation ◽  
Fitness Function ◽  
Three Dimensional ◽  
Simulation Models ◽  
Oxide Semiconductor ◽  
Standard Cell ◽  
The Impact

The project Meeting the Design Challenges of nano-CMOS Electronics ( http://www.nanocmos.ac.uk ) was funded by the Engineering and Physical Sciences Research Council to tackle the challenges facing the electronics industry caused by the decreasing scale of transistor devices, and the inherent variability that this exposes in devices and in the circuits and systems in which they are used. The project has developed a grid-based solution that supports the electronics design process, incorporating usage of large-scale high-performance computing (HPC) resources, data and metadata management and support for fine-grained security to protect commercially sensitive datasets. In this paper, we illustrate how the nano-CMOS (complementary metal oxide semiconductor) grid has been applied to optimize transistor dimensions within a standard cell library. The goal is to extract high-speed and low-power circuits which are more tolerant of the random fluctuations that will be prevalent in future technology nodes. Using statistically enhanced circuit simulation models based on three-dimensional atomistic device simulations, a genetic algorithm is presented that optimizes the device widths within a circuit using a multi-objective fitness function exploiting the nano-CMOS grid. The results show that the impact of threshold voltage variation can be reduced by optimizing transistor widths, and indicate that a similar method could be extended to the optimization of larger circuits.

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