Academic literature on the topic 'Multi level linear modelling'
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Journal articles on the topic "Multi level linear modelling"
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Baky, Ibrahim A. "Solving multi-level multi-objective linear programming problems through fuzzy goal programming approach." Applied Mathematical Modelling 34, no. 9 (September 2010): 2377–87. http://dx.doi.org/10.1016/j.apm.2009.11.004.
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Baky, Ibrahim A. "Interactive TOPSIS algorithms for solving multi-level non-linear multi-objective decision-making problems." Applied Mathematical Modelling 38, no. 4 (February 2014): 1417–33. http://dx.doi.org/10.1016/j.apm.2013.08.016.
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Mole, Melissa A., Mark A. Davidson, Ian L. Turner, Kristen D. Splinter, Ian D. Goodwin, and Andrew D. Short. "MODELLING MULTI-DECADAL SHORELINE VARIABILITY AND EVOLUTION." Coastal Engineering Proceedings 1, no. 33 (December 14, 2012): 98. http://dx.doi.org/10.9753/icce.v33.sediment.98.
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A robust and practical methodology for predicting future shoreline behaviour along sandy coastlines would be valuable to a broad range of coastal engineering applications. Present approaches for predicting shoreline evolution range from simple linear trend models, which cannot predict observed complex behaviour, to coupled hydrodynamic / sediment transport models, with seasonal to multi-year forecasting generally beyond present model capabilities. In this work a simple empirical shoreline variability model, ShoreFor (Shoreline Forecast), is investigated using a multi-decadal dataset to assess model performance at daily to decadal timescales. Model performance is assessed at five alongshore locations within an embayed study site that experience varying exposure to the offshore wave climate due to prominent adjacent headlands and display alongshore variable behaviour. To determine model sensitivity to input wave conditions, both the measured offshore and transformed (modelled) nearshore wave data are used and results compared. Strengths and limitations of the ShoreFor model are identified and discussed, along with ongoing model development and planned application of this modelling technique for shoreline forecasting using future water level and wave climate scenarios.
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ABO-SINNA, MAHMOUD A., and AZZA H. AMER. "TOPSIS Approach for Solving Bi-Level Non-Linear Fractional MODM Problems." JOURNAL OF ADVANCES IN MATHEMATICS 13, no. 4 (February 9, 2018): 7353–70. http://dx.doi.org/10.24297/jam.v13i4.6243.
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TOPSIS (technique for order preference similarity to ideal solution) is considered one of the known classical multiple criteria decision making (MCDM) methods to solve bi-level non-linear fractional multi-objective decision making (BL-NFMODM) problems, and in which the objective function at each level is considered nonlinear and maximization type fractional functions. The proposed approach presents the basic terminology of TOPSIS approach and the construction of membership function for the upper level decision variable vectors, the membership functions of the distance functions from the positive ideal solution (PIS) and of the distance functions from the negative ideal solution (NIS). Thereafter a fuzzy goal programming model is adopted to obtain compromise optimal solution of BL-NFMODM problems. The proposed approach avoids the decision deadlock situations in decision making process and possibility of rejecting the solution again and again by lower level decision makers. The presented TOPSIS technique for BL-NFMODM problems is a new fuzzy extension form of TOPSIS approach suggested by Baky and Abo-Sinna (2013) (Applied Mathematical Modelling, 37, 1004-1015, 2013) which dealt with bi -level multi-objective decision making (BL-MODM) problems. Also, an algorithm is presented of the new fuzzy TOPSIS approach for solving BL-NFMODM problems. Finally, an illustrative numerical example is given to demonstrate the approach.
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Kratica, Jozef, Djordje Dugošija, and Aleksandar Savić. "A new mixed integer linear programming model for the multi level uncapacitated facility location problem." Applied Mathematical Modelling 38, no. 7-8 (April 2014): 2118–29. http://dx.doi.org/10.1016/j.apm.2013.10.012.
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Hanewald, Katja, Han Li, and Adam W. Shao. "Modelling multi-state health transitions in China: a generalised linear model with time trends." Annals of Actuarial Science 13, no. 1 (July 2, 2018): 145–65. http://dx.doi.org/10.1017/s1748499518000167.
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AbstractRapid population ageing in China has urged the need to understand health transitions of older Chinese to assist the development of social security programmes and financial products aimed at funding long-term care. In this paper, we develop a new flexible approach to modelling health transitions in a multi-state Markov model that allows for age effects, time trends and age-time interactions. The model is implemented in the generalised linear modelling framework. We apply the model to evaluate health transitions of Chinese elderly using individual-level panel data from the Chinese Longitudinal Healthy Longevity Survey for the period 1998–2012. Our results confirm that time trends and age–time interactions are important factors explaining health transitions in addition to the more commonly used age effects. We document that differences in disability and mortality rates continue to persist between urban and rural older Chinese. We also compute life expectancies and healthy life expectancies based on the proposed model as inputs for the development of aged care and financial services for older Chinese.
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Eyarkai Nambi, Vijayaram, Kuladaisamy Thangavel, Annamalai Manickavasagan, and Sultan Shahir. "Comprehensive ripeness-index for prediction of ripening level in mangoes by multivariate modelling of ripening behaviour." International Agrophysics 31, no. 1 (January 1, 2017): 35–44. http://dx.doi.org/10.1515/intag-2016-0025.
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Abstract Prediction of ripeness level in climacteric fruits is essential for post-harvest handling. An index capable of predicting ripening level with minimum inputs would be highly beneficial to the handlers, processors and researchers in fruit industry. A study was conducted with Indian mango cultivars to develop a ripeness index and associated model. Changes in physicochemical, colour and textural properties were measured throughout the ripening period and the period was classified into five stages (unripe, early ripe, partially ripe, ripe and over ripe). Multivariate regression techniques like partial least square regression, principal component regression and multi linear regression were compared and evaluated for its prediction. Multi linear regression model with 12 parameters was found more suitable in ripening prediction. Scientific variable reduction method was adopted to simplify the developed model. Better prediction was achieved with either 2 or 3 variables (total soluble solids, colour and acidity). Cross validation was done to increase the robustness and it was found that proposed ripening index was more effective in prediction of ripening stages. Three-variable model would be suitable for commercial applications where reasonable accuracies are sufficient. However, 12-variable model can be used to obtain more precise results in research and development applications.
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Niekamp, Rainer, Damijan Markovic, Adnan Ibrahimbegovic, Hermann G. Matthies, and Robert L. Taylor. "Multi‐scale modelling of heterogeneous structures with inelastic constitutive behavior." Engineering Computations 26, no. 1/2 (January 2, 2009): 6–28. http://dx.doi.org/10.1108/02644400910924780.
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PurposeThe purpose of this paper is to consider the computational tools for solving a strongly coupled multi‐scale problem in the context of inelastic structural mechanics.Design/methodology/approachIn trying to maintain the highest level of generality, the finite element method is employed for representing the microstructure at this fine scale and computing the solution. The main focus of this work is the implementation procedure which crucially relies on a novel software product developed by the first author in terms of component template library (CTL).FindingsThe paper confirms that one can produce very powerful computational tools by software coupling technology described herein, which allows the class of complex problems one can successfully tackle nowadays to be extended significantly.Originality/valueThis paper elaborates upon a new multi‐scale solution strategy suitable for highly non‐linear inelastic problems.
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Radics, K., J. Bartholy, and R. Pongrácz. "Modelling studies of wind field on urban environment." Atmospheric Chemistry and Physics Discussions 2, no. 6 (November 11, 2002): 1979–2001. http://dx.doi.org/10.5194/acpd-2-1979-2002.
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Abstract. Increasing load of air pollution in urban environment emphasises the need for detailed evaluation of wind characteristics that significantly affect the air quality of urban areas, especially, in large agglomerations. This paper includes analysis of urban wind climatology and estimation of wind profiles based on measurements of the new urban climate station located at the Eötvös University, observations of the meteorological station network of the Budapest agglomeration area, and multi-level wind measurements near Hegyhátsál. Furthermore, wind field modelling (using the WAsP linear spectral wind flow model) is presented over selected representative complex areas that demonstrates strong dependence between wind, height, topography, and roughness.
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Mandal, Sumit, Simon Annaheim, Martin Camenzind, and René M. Rossi. "Characterization and modelling of thermal protective performance of fabrics under different levels of radiant-heat exposures." Journal of Industrial Textiles 48, no. 7 (February 28, 2018): 1184–205. http://dx.doi.org/10.1177/1528083718760801.
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The investigation of thermal protective performance of fabrics is highly relevant in order to procure and further develop the firefighters' protective clothing. Therefore, this paper aims at investigating the thermal protective performance of fabrics used in firefighters' clothing under different levels of radiant-heat exposures. For this, properties of a set of thermal protective single- and multi-layered fabrics were measured, and these fabrics were tested under radiant-heat exposures using the Method B of ISO 6942:2002 standard. During the testing, fabrics were exposed to low (10 kW/m2), medium (40 kW/m2), and high (80 kW/m2) intensity radiant-heat exposures; and the heat transfer level (i.e., time required to increase the skin temperature of a wearer/firefighter by certain degrees) through these fabrics were calculated to measure their thermal protective performance. The effects of fabric parameters, structures, properties, and radiant-heat intensities on the protective performance were characterized, and fabric properties that significantly affected the protective performance were statistically identified at different level of radiant-heat exposures. It has been found that weight, thickness, thermal resistance, and evaporative resistance can positively affect the protective performance. Also, the significant fabric properties affecting the protective performance vary for single- and multi-layered fabrics. By using these significant properties, the protective performance of single- and multi-layered fabrics were also separately predicted by mathematical models, i.e., multiple linear regression models and multiple logarithmic regression models. As per the findings of this study, multiple linear regression models can effectively be used to predict the thermal protective performance of fabrics. This study will lead towards building a better understanding and prediction of thermal protective performance of fabrics under radiant-heat exposures.
Dissertations / Theses on the topic "Multi level linear modelling"
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Cook, Sarah Elizabeth. "Multi level Monte Carlo methods for atmospheric dispersion modelling." Thesis, University of Bath, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616582.
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The Met Office uses the NAME dispersion model to solve stochastic differential equations (SDEs) for predicting the transport and spread of atmospheric pollutants. Time stepping methods for this SDE dominate the computation time. In particular the slow convergence of the Monte Carlo Method imposes limitations on the accuracy with which predictions can be made on operational timescales. We review the theory of both the Standard and Multi Level Monte Carlo Methods, and in particular the complexity theorems discussed in [9] in a more general context. We then argue how it can potentially give rise to significant gains for this problem in atmospheric dispersion modelling. To verify these theoretical arguments numerically, we consider two model problems; a simplified problem which corresponds to homogeneous turbulence and is used by the Met Office for long term predictions, as well as a full non-linear model problem close to that used by the Met Office for atmospheric dispersion modelling. For both model problems we performed numerical tests in which we observed significant speed-up as a result of the implementation of the Multi Level Monte Carlo Method. The numerically observed convergence rates are also confirmed by a full theoretical analysis for the simplified model problem.
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Marioni, Luca. "Modélisation numerique et couplage électromagnétique-CFD dans les procédés decoulée." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM011/document.
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Beaucoup de procédés utilisés dans l'industrie sidérurgique (coulée de lingots,coulée continue, …) peuvent générer des défauts : macro-ségrégation, mauvaises propriétés de la microstructure, défauts surfaciques. Ces problèmes peuvent être résolus par un contrôle de la température et de l’écoulement d'acier liquide. Le brassage électromagnétique (EMS) est une technique largement utilisée pour contrôler l’écoulement d'acier liquide par l’imposition d'un champ électromagnétique. Cette technique est complexe car elle couple plusieurs types de problèmes physiques:écoulement multiphasique, solidification,transfert de chaleur et induction électromagnétique à basse fréquence.En outre, l’approche expérimentale est difficile de par la dimension,l'environnement et le coût des procédés considérés. Pour ces raisons, des simulations numériques efficaces sont nécessaires pour comprendre les applications EMS et améliorer les procédés évoqués. L'objectif de cette thèse est de développer une méthodologie numérique robuste,efficace et précise pour la simulation multi-physique de l'EMS, en particulier pour le brassage dans le moule dans le cadre de la coulée continue d'acier. Cette méthodologie a été mise en oeuvre dans le code commercial THERCAST® pour être utilisé dans le cadre d’applications industriellesMany of the processes used in thesteelmaking industry (e.g. ingot casting,continuous casting, …) can lead todefects: macro-segregation, poormicrostructure properties, surfacedefects. These issues can be solved bycontrolling the temperature and the flowof molten steel. Electromagnetic stirring(EMS) is a widely used technique to steerthe flow of liquid steel by thesuperimposition of an electro-magneticfield. This application is complex becauseit couples several physical problems:multi-phase flow, solidification, heattransfer and low frequency electromagneticinduction. In addition,experimental work is difficult because ofthe size, environment and cost of theconsidered processes. For thesereasons, efficient and effective numericalsimulations are needed to understandEMS applications and improve theaforementioned processes.The objective of this thesis is to developa robust, efficient and accurate numericalprocedure for the multi-physicssimulation of EMS, especially for in-moldstirring in the framework of continuouscasting of steel. This procedure has beenimplemented in the commercial codeTHERCAST® in order to be used forindustrial applications
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Carvalho, Vanessa Viana da Silva. "Generation of multi-level and multi-user games through modelling in hierarchical coloured Petri nets." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13488.
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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorThis work presents a method to generate games with multilevel and multiple users using Hierarchical Coloured Petri Nets. The design of a multiuser game containing multiple navigation environments (multilevel) is made from the model of a Hierarchical Coloured Petri Net, in which are specified all of the rules, properties and structures of the game. The created model for the game can be formally analysed, verifying the existence of deadlocks and invalid paths, for example, and others possible conception problems, that can be done with the tools available on CPN Tools. To validate this method, a tool has been developed, called CPN Games, which allows fast and dynamic development of simple conception games only using Hierarchical Coloured Petri Nets. The XML codes of the designed models in CPN Tools are interpreted by CPN Games following a set of predefined rules to instantiate different games, without additional programing. It is demonstrated the mechanisms of the design, analysis and validation of the models and finally it is presented several examples of games developed by this tool.
Este trabalho apresenta um mÃtodo para geraÃÃo de jogos multinÃveis e com mÃltiplos usuÃrios por meio de modelagem em Redes de Petri Coloridas HierÃrquicas. A concepÃÃo de um jogo multiusuÃrio, contendo mÃltiplos ambientes de navegaÃÃo (multinÃveis), à feita a partir da criaÃÃo de um modelo hierÃrquico em Rede de Petri Colorida, no qual se especificam todas as regras, propriedades e estruturas do jogo. O modelo criado para o jogo pode ser analisado formalmente, verificando-se, por exemplo, a existÃncia de bloqueios e de transiÃÃes mortas (caminhos invÃlidos), entre outros possÃveis problemas de concepÃÃo, o que pode ser feito com a utilizaÃÃo de ferramentas disponÃveis no CPN Tools. Para validar esse mÃtodo, foi concebida uma ferramenta, denominada CPN Games, que permite o desenvolvimento rÃpido e dinÃmico de jogos de concepÃÃo simples exclusivamente por Rede de Petri Colorida HierÃrquica. Os cÃdigos em XML de modelos constituÃdos com o CPN Tools sÃo interpretadas pelo CPN Games seguindo um conjunto de regras prà estabelecidas para instanciar diferentes jogos, sem a necessidade de programaÃÃo adicional. SÃo demonstrados os mecanismos de criaÃÃo, anÃlise e validaÃÃo dos modelos e diferentes exemplos de jogos construÃdos com a ferramenta.
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Ghorashi, Ali. "Linear decentralised modelling for H Control of a Multi-Axis simulation table." Thesis, University of Bath, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.518127.
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Harper, John Stuart. "Analytic cache modelling of numerical programs." Thesis, University of Warwick, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343887.
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Anwar, Muslimin. "Modelling exchange rates and monetary policy in emerging Asian economies : non-linear econometric approach." Thesis, Brunel University, 2007. http://bura.brunel.ac.uk/handle/2438/4865.
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In this thesis we examine exchange rates and monetary policy of four emerging Asian countries, namely Indonesia, Malaysia, the Philippines and South Korea. We model equilibrium exchange rates using a general behavioural specification consistent with a variety of theoretical approaches; and short-run dynamics using a general non-linear adjustment model. We find in all countries examined, equilibrium nominal and real exchange rates are a function of permanent relative output and one or more variables from domestic and foreign price levels, nominal and real interest rate differentials, the level of and changes in net foreign assets, and a time trend. These results imply that individual countries present significant elements of idiosyncratic behaviour, casting doubt on empirical models using panel-data techniques. We also obtain evidence of non-linear exchange rate dynamics, with the speed of adjustment to equilibrium being in all cases a function of the size, and in two cases, the sign of the misalignment term. With respect to monetary policy, we examined these countries' monetary policy reaction function based on an open economy augmented Taylor rule including the exchange rate and the foreign interest rate. Using a formal testing approach, our tests reject linearity, suggesting that monetary authorities in these four emerging economies are subject to nonlinear inflation effects and that they respond more vigorously to inflation when it is further from the target. Our results also lead us to speculate that policymakers in three countries may have been attempting to keep inflation within the range, while those in the other country may have been pursuing a point inflation target. Finally, we also find monetary policy is asymmetric as policy makers respond differently to upward and downward deviations of inflation away from the target.
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Parks, Kathrin Ann. "A formula for low achievement using multi-level models to understand the impact of individual level effects and school level effects on mathematics achievement /." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969/172.
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Catalán, Pallarés Sandra. "Multithreaded Dense Linear Algebra on Asymmetric Multi-core Processors." Doctoral thesis, Universitat Jaume I, 2018. http://hdl.handle.net/10803/461918.
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This dissertation targets two important problems. The first one is the design of low-level DLA kernels for architectures comprising two (or more) classes of cores. The main question we have to address here is how to attain a balanced distribution of the computational workload among the heterogeneous cores while taking into account that some of the resources, in particular cache levels, are either shared or private. The second question is partially related to the first one. Concretely, this dissertation explores an alternative to runtime-based systems in order to extract “sufficient" parallelism from complex DLA operations while making an efficient use of the cache hierarchy of the architecture. Thus, the main goal of this thesis is the study, design, development and analysis of experimental solutions that are architecture-aware for the execution of DLA operations on low power architectures, more specically asymmetric platforms.Esta tesis doctoral aborda dos problemas importantes. El primero es el diseño de kernels DLA de bajo nivel para arquitecturas compuestas por dos (o más) tipos de cores. La principal cuestión en este caso es como obtener un distribución de carga computacional balanceada entre los cores heterogéneos mientras se tiene en cuenta que algunos recursos, en particular los niveles de cache, son bien compartidos o privados. La segunda cuestión está parcialmente relacionada con la primera. Concretamente, en la teis se explora un alternativa a los sistemas basados en runtimes para extraer paralelismo sufciente para operaciones DLA complejas mientras se hace un uso eficiente de la jerarquía de cache de la arquitectura. Por tanto, el objetivo general de esta tesis es el estudio, diseño, desarrollo y análsis de soluciones experimentales que son conscientes de la arquitectura para la ejecución de operaciones DLA en arquitecturas de bajo consumo, más concretamente sistemas asimétricos.
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Aggidis, Eur Ing George A. "A sequential multi-level generic decision support modelling tool for the development of energy projects." Thesis, Lancaster University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.551648.
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An imaginative development of renewable energy schemes leads to power generation where the energy was previously dissipated. This thesis describes a generic model that integrates disciplines to address the barriers to deployment of hydro schemes; it uses North-West England as a case study for demonstration. The model focuses on the need to make an economic decision as to whether development is appropriate or not and is defined by a loop that links essential questions. Decision making is complex requiring a variety of data sources as evidence and forms of evaluation, in order to simplify, the process progresses through a number of iterations. By starting with simple questions regarding each component and identifying obvious show-stoppers the advice on the decision is made efficiently. Each iteration requires more detailed assessment, but by posing simple questions first, time is not wasted in solving detailed problems in one area before finding that the development is stymied by a much simpler issue in a later section of the loop. The decision requires information from a number of sources starting with the energy available at different times of year and under different conditions. To maximise the value of the research carried out, the model has been presented as a web- based tool', freely available to anyone with internet access. The tool follows standard web protocols and is intuitive in its application, using a hierarchy of menus. To demonstrate the operation of the model the quantitative aspects of the first iteration round the loop are described. Further iterations are presented without quantification. Schemes in different stages of development have been investigated ranging from initial concepts through to operating hydro systems. One scheme, at Heron Corn Mill on the river Bela just south of Milnthorpe has progressed through the course of this research from an initial idea through to a functioning power plant.
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Patel, Meena. "Numerical study of non-linear spectroscopy and four-wave-mixing in two and multi-level atoms." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2623.
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Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2018.In this research, we undertake a numerical study of the interaction between laser beams and two as well as multi-level atoms. The main aim of this research is to obtain a deeper understanding of laser-atom interactions and non-linear processes such as optical four-wave mixing. This work will supplement experiments to be conducted by other members of the group, who are involved in generating entangled photons via four-wave mixing in cold rubidium atoms. We begin by performing a basic study of the interaction between laser beams and two-level atoms as an aid to gain knowledge of numerical techniques, as well as an understanding of the physics behind light-atom interactions. We make use of a semi-classical approach to describe the system where the atoms are treated quantum mechanically and the laser beams are treated classically. We study the interaction between atoms and laser beams using the density matrix operator and Maxwell's equations respectively. By solving the optical Bloch equations for two-level atoms we examine the atomic populations and coherences and present plots of the density matrix elements as a function of time. The e ects of various parameters such as laser intensity, detuning and laser modulation have been tested. The behaviour of the laser beam as it propagates through the atomic sample is also studied. This is determined by Maxwell's equation where the atomic polarization is estimated from the coherence terms of the density matrix elements.
French South African Institute of Technology National Research Foundation
Books on the topic "Multi level linear modelling"
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Blair, Charles. The computational complexity of multi-level linear programs. Urbana-Champaign]: College of Commerce and Business Administration, Bureau of Economic and Business Research, University of Illinois Urbana-Champaign, 1989.
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Gould, Myles. Health service restructuring and geographically based analysis: With reference to the multi-level modelling of immunization uptake. Cardiff: Wales and South West Regional Research Laboratory, 1991.
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Svetozar, Margenov, ed. Robust algebraic multilevel methods and algorithms. Berlin: Walter De Gruyter, 2009.
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Multi-Level Modelling. SAGE Publications, Limited, 2010.
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Kraus, Johannes, and Svetozar Margenov. Robust Algebraic Multilevel Methods and Algorithms. De Gruyter, Inc., 2009.
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Levin, Frank S. Quantum Boxes, Stringed Instruments. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198808275.003.0008.
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Chapter 7 illustrates the results obtained by applying the Schrödinger equation to a simple pedagogical quantum system, the particle in a one-dimensional box. The wave functions are seen to be sine waves; their wavelengths are evaluated and used to calculate the quantized energies via the de Broglie relation. An energy-level diagram of some of the energies is constructed; on it are illustrations of the corresponding wave functions and probability distributions. The wave functions are seen to be either symmetric or antisymmetric about the midpoint of the line representing the box, thereby providing a lead-in to the later exploration of certain symmetry properties of multi-electron atoms. It is next pointed out that the Schrödinger equation for this system is identical to Newton’s equation describing the vibrations of a stretched musical string. The different meaning of the two solutions is discussed, as is the concept and structure of linear superpositions of them.
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Djurfeldt, Agnes Andersson, Göran Djurfeldt, Ola Hall, and Maria Archila Bustos. Agrarian Change and Structural Transformation: Drivers and Distributional Outcomes. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198799283.003.0005.
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This chapter examines agrarian changes triggered by the structural transformation of the overall economy, focusing on their drivers and distributional outcomes. By means of multi-level modelling of three processes—intensification of grain yields, diversification of cropping, and non-farm diversification (pluriactivity)—it concludes that intensification has moderately accelerated and is getting more important than its twin process. Similarly, crop diversification has accelerated, while non-farm diversification seems to be more pull- than push-driven. The most important drivers of the two first-mentioned processes are commercial ones: increasing local and domestic demand for grains and for other crops and institutional changes promoting market participation of smallholders. The chapter concludes that these processes are not pro-poor, but neither are they pro-rich; middling smallholder households tend to be more involved. The gender profile of agricultural diversification seems to involve and benefit male-managed farms, whereas non-farm diversification is gender neutral.
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Sobczyk, Eugeniusz Jacek. Uciążliwość eksploatacji złóż węgla kamiennego wynikająca z warunków geologicznych i górniczych. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN, 2022. http://dx.doi.org/10.33223/onermin/0222.
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Hard coal mining is characterised by features that pose numerous challenges to its current operations and cause strategic and operational problems in planning its development. The most important of these include the high capital intensity of mining investment projects and the dynamically changing environment in which the sector operates, while the long-term role of the sector is dependent on factors originating at both national and international level. At the same time, the conditions for coal mining are deteriorating, the resources more readily available in active mines are being exhausted, mining depths are increasing, temperature levels in pits are rising, transport routes for staff and materials are getting longer, effective working time is decreasing, natural hazards are increasing, and seams with an increasing content of waste rock are being mined. The mining industry is currently in a very difficult situation, both in technical (mining) and economic terms. It cannot be ignored, however, that the difficult financial situation of Polish mining companies is largely exacerbated by their high operating costs. The cost of obtaining coal and its price are two key elements that determine the level of efficiency of Polish mines. This situation could be improved by streamlining the planning processes. This would involve striving for production planning that is as predictable as possible and, on the other hand, economically efficient. In this respect, it is helpful to plan the production from operating longwalls with full awareness of the complexity of geological and mining conditions and the resulting economic consequences. The constraints on increasing the efficiency of the mining process are due to the technical potential of the mining process, organisational factors and, above all, geological and mining conditions. The main objective of the monograph is to identify relations between geological and mining parameters and the level of longwall mining costs, and their daily output. In view of the above, it was assumed that it was possible to present the relationship between the costs of longwall mining and the daily coal output from a longwall as a function of onerous geological and mining factors. The monograph presents two models of onerous geological and mining conditions, including natural hazards, deposit (seam) parameters, mining (technical) parameters and environmental factors. The models were used to calculate two onerousness indicators, Wue and WUt, which synthetically define the level of impact of onerous geological and mining conditions on the mining process in relation to: —— operating costs at longwall faces – indicator WUe, —— daily longwall mining output – indicator WUt. In the next research step, the analysis of direct relationships of selected geological and mining factors with longwall costs and the mining output level was conducted. For this purpose, two statistical models were built for the following dependent variables: unit operating cost (Model 1) and daily longwall mining output (Model 2). The models served two additional sub-objectives: interpretation of the influence of independent variables on dependent variables and point forecasting. The models were also used for forecasting purposes. Statistical models were built on the basis of historical production results of selected seven Polish mines. On the basis of variability of geological and mining conditions at 120 longwalls, the influence of individual parameters on longwall mining between 2010 and 2019 was determined. The identified relationships made it possible to formulate numerical forecast of unit production cost and daily longwall mining output in relation to the level of expected onerousness. The projection period was assumed to be 2020–2030. On this basis, an opinion was formulated on the forecast of the expected unit production costs and the output of the 259 longwalls planned to be mined at these mines. A procedure scheme was developed using the following methods: 1) Analytic Hierarchy Process (AHP) – mathematical multi-criteria decision-making method, 2) comparative multivariate analysis, 3) regression analysis, 4) Monte Carlo simulation. The utilitarian purpose of the monograph is to provide the research community with the concept of building models that can be used to solve real decision-making problems during longwall planning in hard coal mines. The layout of the monograph, consisting of an introduction, eight main sections and a conclusion, follows the objectives set out above. Section One presents the methodology used to assess the impact of onerous geological and mining conditions on the mining process. Multi-Criteria Decision Analysis (MCDA) is reviewed and basic definitions used in the following part of the paper are introduced. The section includes a description of AHP which was used in the presented analysis. Individual factors resulting from natural hazards, from the geological structure of the deposit (seam), from limitations caused by technical requirements, from the impact of mining on the environment, which affect the mining process, are described exhaustively in Section Two. Sections Three and Four present the construction of two hierarchical models of geological and mining conditions onerousness: the first in the context of extraction costs and the second in relation to daily longwall mining. The procedure for valuing the importance of their components by a group of experts (pairwise comparison of criteria and sub-criteria on the basis of Saaty’s 9-point comparison scale) is presented. The AHP method is very sensitive to even small changes in the value of the comparison matrix. In order to determine the stability of the valuation of both onerousness models, a sensitivity analysis was carried out, which is described in detail in Section Five. Section Six is devoted to the issue of constructing aggregate indices, WUe and WUt, which synthetically measure the impact of onerous geological and mining conditions on the mining process in individual longwalls and allow for a linear ordering of longwalls according to increasing levels of onerousness. Section Seven opens the research part of the work, which analyses the results of the developed models and indicators in individual mines. A detailed analysis is presented of the assessment of the impact of onerous mining conditions on mining costs in selected seams of the analysed mines, and in the case of the impact of onerous mining on daily longwall mining output, the variability of this process in individual fields (lots) of the mines is characterised. Section Eight presents the regression equations for the dependence of the costs and level of extraction on the aggregated onerousness indicators, WUe and WUt. The regression models f(KJC_N) and f(W) developed in this way are used to forecast the unit mining costs and daily output of the designed longwalls in the context of diversified geological and mining conditions. The use of regression models is of great practical importance. It makes it possible to approximate unit costs and daily output for newly designed longwall workings. The use of this knowledge may significantly improve the quality of planning processes and the effectiveness of the mining process.
Book chapters on the topic "Multi level linear modelling"
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Burton, Paul, Lyle Gurrin, and Peter Sly. "Clustered Data: Extending the Simple Linear Regression Model to Account for Correlated Responses: An Introduction to Generalized Estimating Equations and Multi-Level Mixed Modelling." In Tutorials in Biostatistics, 1–33. Chichester, UK: John Wiley & Sons, Ltd, 2005. http://dx.doi.org/10.1002/0470023724.ch1a.
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Lee, E. Stanley, and Hsu-shih Shih. "Linear Bi-level Programming." In Fuzzy and Multi-Level Decision Making, 11–48. London: Springer London, 2001. http://dx.doi.org/10.1007/978-1-4471-0683-8_2.
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Cheng, Chi-Bin, Hsu-Shih Shih, and E. Stanley Lee. "Linear Bi-level Programming." In Fuzzy and Multi-Level Decision Making: Soft Computing Approaches, 15–72. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-92525-7_2.
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Glasdam, Jakob Bærholm. "Multi-level Converter Modelling and Evaluation." In Harmonics in Offshore Wind Power Plants, 89–104. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-26476-9_6.
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Lachmann, Matthias, and Klaus Neumann. "A Heuristic for Multi-Product, Multi-Period, Single-Level Batch Production." In Mathematical Modelling in Economics, 423–33. Berlin, Heidelberg: Springer Berlin Heidelberg, 1993. http://dx.doi.org/10.1007/978-3-642-78508-5_41.
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Atkinson, Colin, Ralph Gerbig, and Bastian Kennel. "On-the-Fly Emendation of Multi-level Models." In Modelling Foundations and Applications, 194–209. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-31491-9_16.
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Renaud, Paul S. A. "A theoretical model of a multi-level government." In Applied Political Economic Modelling, 120–55. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-83912-2_8.
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Rossini, Alessandro, Juan de Lara, Esther Guerra, and Nikolay Nikolov. "A Comparison of Two-Level and Multi-level Modelling for Cloud-Based Applications." In Modelling Foundations and Applications, 18–32. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-21151-0_2.
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Fuchs, L. "Turbulence Modelling as a Multi-Level Approach." In Multigrid Methods IV, 35–42. Basel: Birkhäuser Basel, 1994. http://dx.doi.org/10.1007/978-3-0348-8524-9_3.
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Henderson-Sellers, Brian. "Random Thoughts on Multi-level Conceptual Modelling." In Lecture Notes in Computer Science, 93–116. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-17505-3_5.
Full textConference papers on the topic "Multi level linear modelling"
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Chen, Zhen, Tareq Shaalan, and Ali Dogru. "A Multi-Level Non-Linear Solver for Complex Well Modelling." In SPE Reservoir Simulation Conference. SPE, 2021. http://dx.doi.org/10.2118/204009-ms.
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Abstract Complex well model has proved to be important for capturing the full physics in wellbore, including pressure losses, multiphase effects, and advanced device modelling. Numerical instability may be observed especially when the well is produced at a low rate from a highly productive multi-phase zone. In this paper, a new multi-level nonlinear solver is presented in a state-of-the-art parallel complex wellbore model for addressing some difficult numerical convergence problems. A sequential two-level nonlinear solver is implemented, where the inner solver is used to address the convergence in the constraint rate equation, and then the entire complex network is solved using an outer solver. Finally, the wellbore model is coupled with the grid solution explicitly, sequentially, or implicitly. This novel formulation is robust enough to greatly improve the numerical stability due to the lagging in the computation of mixture density in wellbore constraint rate equation and the variation in the fluid composition over Newton iterations in network nonlinear solver. The numerical challenge in the complex well model and the improvement of performance with the new nonlinear solver are demonstrated using reservoir simulation. Models with complex wells running into convergence problems are constructed and simulated. With this novel nonlinear solver, simulation gives much more reliable results on well productions without numerical oscillations and computational cost is much less.
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Caddemi, Salvatore, Ivo Caliò, Francesco Cannizzaro, Domenico D'Urso, Bartolomeo Pantò, Davide Rapicavoli, and Giuseppe Occhipinti. "3D Discrete Macro-Modelling Approach for Masonry Arch Bridges." In IABSE Symposium, Guimarães 2019: Towards a Resilient Built Environment Risk and Asset Management. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/guimaraes.2019.1825.
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<p>Masonry multi-span arch bridges are historical structures still playing a key role in many transportation networks of numerous countries. Most of these bridges are several decades old and have been subjected to continuous dynamic loadings, due to the vehicular traffic, and in many cases their maintenance required structural modifications. The currently adopted health monitoring strategies are based on in situ inspections as well as structural assessments based on numerical models characterised by different levels of reliability according to the required purpose. Simplified approaches are generally adopted for fast structural evaluation, on the other hand more rigorous approaches are fundamental for a reliable structural assessment of these particular structures, often characterized by very complex geometrical layouts and structural alterations not always sufficiently documented. This paper presents an original Discrete Macro-Element Method (DMEM) that allows a reliable simulation of the linear and nonlinear response of masonry structures and masonry bridges characterised by a lower computational burden, compared to classical nonlinear FEM analyses, although maintaining a good accuracy. The method is applied to a real masonry bridges and the results are compared with those obtained from a more sophisticated three- dimensional nonlinear FEM model both in linear and nonlinear context.</p>
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He, Weijing, Liwu Wei, and Simon Smith. "Intensive Validation of Computer Prediction of Welding Residual Stresses in a Multi-Pass Butt Weld." In ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-20490.
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Welding and joining technology is fundamental to offshore engineering. The construction of engineering facilities and pipelines requires the extensive use of welding and associated structural integrity assessments of safety critical or heavily loaded sections. Proof of integrity is based upon the externally applied loads and in service stresses as well as the welding residual stresses. The level and distribution of residual stresses arises from the complex thermo-mechanical history of heat flow and thermal expansion at very high temperatures during welding, so it has not been possible to make very accurate assessments of these in the same way that service stresses can be defined. Conservative assumptions are therefore made and this often means that the as-welded stresses are assumed to be of yield magnitude. The peak values of stress may well be very high, but the shrinkage of the latter passes of multi-pass welds may compress earlier passes giving rise to much lower levels of stress. There is considerable engineering interest in the utilisation of lower levels of residual stress where they exist or of the design of welds with lower residual stresses in sensitive areas such as the weld root. Currently there is no single technique that can claim to provide cost effective, accurate distributions of residual stresses in welds. The current paper provides an important contribution to the understanding of measurement and prediction techniques. It describes an extensive set of measurements taken on a girth butt weld. The weld was made using submerged arc and was made in 18 passes. The pipe was X52 with a 32mm wall thickness and 910mm outside diameter. Temperature, strain and displacement values were measured throughout the production of the weld. The intermediate values between each pass were recorded as well as the time varying history during the production of individual passes. The final through thickness residual stress distribution was measured. Finite Element Analysis (FEA) modelling was undertaken to determine whether modelling could provide a satisfactory prediction of the final residual stresses. Intermediate results were also used to understand the behaviour of the weld and the model more clearly. The modelling used material properties measured on material from a separate specimen. The weld cross section was identified for each pass so that the heat input method could be developed to represent the actual melt pool conditions of the weld. The measured values of hoop residual stress were up to the yield stress magnitude just below the cap, but were 20% of yield in the root of the weld. The axial residual stresses were less than 50% of yield. Linear kinematic hardening provided the most accurate prediction of residual stress. The hoop stresses were predicted to an accuracy of 10% with this material model. Other hardening models were less accurate, but all models were conservative. The results provide a basis for the adoption of more accurate distributions of residual stresses in Engineering Critical Assessments (ECAs) and assessments of weld performance under fatigue and corrosive conditions.
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Williams, Dara, and Feargal Kenny. "Calculation of VIV Fatigue of Multi-Pipe Systems." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-61089.
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In various regions of the world offshore oil and gas production and exploration is met with the challenges of operating in extreme currents. These extreme current loads increase the risk of vortex induced vibration (VIV) of the riser system and the associated fatigue damage induced by these vibrations. Regions of particular concern are the Gulf of Mexico where strong loop currents occur, East Africa where the Benguela current dominates and regions offshore South America where strong eddy currents can occur. In order to ensure robust riser design for these regions it is necessary to perform detailed evaluations of the expected VIV response of the global riser system. The assessment of VIV response of steel riser systems is commonplace in the industry and there are well established industry practices in relation to this. In addition there are a number of commercially available VIV analysis tools. Whilst commercially available VIV analysis tools have proved effective in the analysis of long slender structures such as risers there are also a number of limitations in the level of complexity of the model that can be achieved. The analysis approach utilized by these models is based on simplified geometries and linearization of complex non-linear interactions. As a result of these simplifications these analysis tools are not suited to the analysis of non-linear multi-pipe models. Many offshore riser configurations consist of one or more pipe or casing strings enclosed by an outer pipe which is exposed to the environment. In a scenario where VIV of the outer pipe occurs then there will also be a corresponding deflection and curvature transmitted to the inner pipe(s). The displacements and associated stresses of the inner pipe(s) are largely dictated by the response of the outer pipe. Thus for multi-pipe configurations where the inner pipe is not constrained by cement or centralisers (e.g. landing string inside marine riser) the issue arises as to how to calculate the fatigue of the inner strings due to VIV oscillation of the outer string. At the time of writing no standard industry approach exists to address this issue and therefore this paper will outline and demonstrate a proposed approach to address this issue. The objective of this paper is to outline a novel analysis approach for the calculation of inner string fatigue resulting from VIV of the outer pipe. This proposed methodology combines the benefit of simplified VIV analysis tools with more detailed non-linear global finite element modelling techniques to enable a more comprehensive and accurate assessment of fatigue life of the complete system. The benefits and effectiveness of the proposed method are demonstrated through the analysis of a series of case studies which include landing string fatigue and riser fatigue for deep water applications.
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Hassan, Marwan, Robert Rogers, and Andrew Gerber. "Time Domain Models for Damping-Controlled Fluidelastic Instability Forces in Multi-Span Tubes With Loose Supports." In ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting collocated with 8th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2010. http://dx.doi.org/10.1115/fedsm-icnmm2010-30781.
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This paper presents simulations of a loosely supported multi-span tube subjected to turbulence and fluidelastic instability forces. Several time-domain fluid force models simulating the damping controlled fluidelastic instability mechanism in tube arrays are presented. These models include the negative damping model based on the Connors equation, fluid force coefficient-based models (Chen; Tanaka and Takahara), and two semi-analytical models (Price and Pai¨doussis; and Lever and Weaver). Time domain modelling challenges for each of these theories are discussed. The implemented models are validated against available experimental data. The linear simulations show that the Connors-equation based model exhibits the most conservative prediction of the critical flow velocity when the recommended design values for the Connors equation are used. The models are then utilized to simulate the nonlinear response of a three-span cantilever tube in a lattice bar support subjected to air crossflow. The tube is subjected to a single-phase flow passing over one of the tubes spans and the flow velocity and the support clearance are varied. Special attention is paid to the tube/support interaction parameters that affect wear, such as impact forces, contact ratio, and normal work rate. As was seen for the linear cases, the reduced flow velocity at the instability threshold differs for the fluid force models considered. The investigated models do, however, exhibit similar response characteristics for the impact force, tip lift response, and work rate, except for the Connors-based model that overestimates the response and the tube/support interaction parameters for the loose support case, especially at large clearances.
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Lu, Ye, Pandeli Temarel, Qiu Jin, Yousheng Wu, Xinyun Ni, and Chao Tian. "Numerical Convergence on the Hydroelasticity of a Large Containership." In ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/omae2019-95200.
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Abstract Nowadays, more and more 20,000 twenty-foot equivalent unit (TEU) class ultra large container ships (ULCS) have been built in service across the worldwide. It is paramount that hydroelastic specialists become paying close attention to structural responses and loads predictions due to up to a 400m length of the ships. First of all, mesh convergence by finite element analysis is necessary to determine in the numerical calculation. In this paper, based on the three-dimension linear frequency domain hydroelasticity theory, the hydrodynamic meshes convergence is discussed when modelling the hull surface of the ULCS. Ascribe to the Sunway TaihuLight, rank 3 in the current TOP500 supercomputer list, the Message Passing Interface and the multi-level parallel programming model are used aimed to the wetted panels, the wave frequencies and so on. Several sets of different global grid density and grid distribution along the ship’s length for the containership are calculated to compare the hydrodynamic coefficients such as added mass, damping, wave exciting force, ship motions and exterior loads with several typical service speeds in the head regular wave. It has been concluded that sensitivity of numerical modelling converges to a stable state with increasing the panel numbers per ship. Therefore, one set of grid division optimised, and superposed elastic modes numbers are recommended in the hydroelastic analysis of numerical hydroelastic prediction of springing and whipping.
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Maggiani, Gianluca, Matthew J. Roy, Simone Colantoni, and Philip J. Withers. "Improved Low Cycle Fatigue Analysis for Ni-Based Turbine Nozzles." In ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/gt2018-75974.
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The requirements for cleaner energy have driven industrial gas turbines manufacturers to increase firing temperatures and improve cooling of nozzles. The application of high temperature alloys having adequate thermo-mechanical requirements is critical, as assessed by low cycle fatigue performance. The effect of higher firing temperatures combined with higher cooling efficiencies has lead to operating cycles where the level of plastic strain imparted define component life. The capability of material models to account for non-linear effects such as ratchetting or shakedown, cyclic hardening or softening as well as Bauschinger or relaxation effects have been highlighted in this context. Neglecting these effects can lead to over and under-conservative life assessment analysis, while accounting for them using standard multilinear material models lead to convergence issues in finite element analysis. In this paper, Chaboche viscoplastic model has been applied to a transient structural of a first stage gas turbine nozzle. Fitting of the model based on experimental mechanical test data on MAR-M-247 alloy will be described, followed by an overview of how the model may be implemented to a benchmark nozzle thermo-mechanical transient analysis. Finally the details how the Chaboche-type model has provided up to 50% decrease in computation time when compared to using a standard multi-linear material modelling approach.
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Whelan, Michael. "An experiment in multi-level modelling." In the 17th conference. New York, New York, USA: ACM Press, 1985. http://dx.doi.org/10.1145/21850.253328.
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Kühne, Thomas, and Arne Lange. "Meaningful metrics for multi-level modelling." In MODELS '20: ACM/IEEE 23rd International Conference on Model Driven Engineering Languages and Systems. New York, NY, USA: ACM, 2020. http://dx.doi.org/10.1145/3417990.3421412.
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Kimoto, Tadahiko. "Evaluation of IGS Quantization for Multi-Level Halftone." In Modelling and Simulation. Calgary,AB,Canada: ACTAPRESS, 2013. http://dx.doi.org/10.2316/p.2013.804-053.
Full textReports on the topic "Multi level linear modelling"
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Schafer, Ingo. Orthogonal and Nonorthogonal Expansions for Multi-Level Logic Synthesis for Nearly Linear Functions and their Application to Field Programmable Gate Array Mapping. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.1338.
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Ayoul-Guilmard, Q., F. Nobile, S. Ganesh, M. Nuñez, R. Tosi, C. Soriano, and R. Rosi. D5.5 Report on the application of multi-level Monte Carlo to wind engineering. Scipedia, 2022. http://dx.doi.org/10.23967/exaqute.2022.3.03.
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We study the use of multi-level Monte Carlo methods for wind engineering. This report brings together methodological research on uncertainty quantification and work on target applications of the ExaQUte project in wind and civil engineering. First, a multi-level Monte Carlo for the estimation of the conditional value at risk and an adaptive algorithm are presented. Their reliability and performance are shown on the time-average of a non-linear oscillator and on the lift coefficient of an airfoil, with both preset and adaptively refined meshes. Then, we propose an adaptive multi-fidelity Monte Carlo algorithm for turbulent fluid flows where multilevel Monte Carlo methods were found to be inefficient. Its efficiency is studied and demonstrated on the benchmark problem of quantifying the uncertainty on the drag force of a tall building under random turbulent wind conditions. All numerical experiments showcase the open-source software stack of the ExaQUte project for large-scale computing in a distributed environment.
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Brophy, Kenny, and Alison Sheridan, eds. Neolithic Scotland: ScARF Panel Report. Society of Antiquaries of Scotland, June 2012. http://dx.doi.org/10.9750/scarf.06.2012.196.
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The main recommendations of the Panel report can be summarised as follows: The Overall Picture: more needs to be understood about the process of acculturation of indigenous communities; about the Atlantic, Breton strand of Neolithisation; about the ‘how and why’ of the spread of Grooved Ware use and its associated practices and traditions; and about reactions to Continental Beaker novelties which appeared from the 25th century. The Detailed Picture: Our understanding of developments in different parts of Scotland is very uneven, with Shetland and the north-west mainland being in particular need of targeted research. Also, here and elsewhere in Scotland, the chronology of developments needs to be clarified, especially as regards developments in the Hebrides. Lifeways and Lifestyles: Research needs to be directed towards filling the substantial gaps in our understanding of: i) subsistence strategies; ii) landscape use (including issues of population size and distribution); iii) environmental change and its consequences – and in particular issues of sea level rise, peat formation and woodland regeneration; and iv) the nature and organisation of the places where people lived; and to track changes over time in all of these. Material Culture and Use of Resources: In addition to fine-tuning our characterisation of material culture and resource use (and its changes over the course of the Neolithic), we need to apply a wider range of analytical approaches in order to discover more about manufacture and use.Some basic questions still need to be addressed (e.g. the chronology of felsite use in Shetland; what kind of pottery was in use, c 3000–2500, in areas where Grooved Ware was not used, etc.) and are outlined in the relevant section of the document. Our knowledge of organic artefacts is very limited, so research in waterlogged contexts is desirable. Identity, Society, Belief Systems: Basic questions about the organisation of society need to be addressed: are we dealing with communities that started out as egalitarian, but (in some regions) became socially differentiated? Can we identify acculturated indigenous people? How much mobility, and what kind of mobility, was there at different times during the Neolithic? And our chronology of certain monument types and key sites (including the Ring of Brodgar, despite its recent excavation) requires to be clarified, especially since we now know that certain types of monument (including Clava cairns) were not built during the Neolithic. The way in which certain types of site (e.g. large palisaded enclosures) were used remains to be clarified. Research and methodological issues: There is still much ignorance of the results of past and current research, so more effective means of dissemination are required. Basic inventory information (e.g. the Scottish Human Remains Database) needs to be compiled, and Canmore and museum database information needs to be updated and expanded – and, where not already available online, placed online, preferably with a Scottish Neolithic e-hub that directs the enquirer to all the available sources of information. The Historic Scotland on-line radiocarbon date inventory needs to be resurrected and kept up to date. Under-used resources, including the rich aerial photography archive in the NMRS, need to have their potential fully exploited. Multi-disciplinary, collaborative research (and the application of GIS modelling to spatial data in order to process the results) is vital if we are to escape from the current ‘silo’ approach and address key research questions from a range of perspectives; and awareness of relevant research outside Scotland is essential if we are to avoid reinventing the wheel. Our perspective needs to encompass multi-scale approaches, so that ScARF Neolithic Panel Report iv developments within Scotland can be understood at a local, regional and wider level. Most importantly, the right questions need to be framed, and the right research strategies need to be developed, in order to extract the maximum amount of information about the Scottish Neolithic.
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Unal, Beyza, Julia Cournoyer, Calum Inverarity, and Yasmin Afina. Uncertainty and complexity in nuclear decision-making. Royal Institute of International Affairs, March 2022. http://dx.doi.org/10.55317/9781784135157.
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Complex systems modelling is already implemented in critical policy areas such as climate change and health. It could also play an important role in the nuclear weapons sphere – by opening alternative pathways that may help mitigate risks of confrontation and escalation – but such modelling has yet to be fully embraced by policymakers in this community. By applying a complexity lens, policy- and decision-makers at all stages along the nuclear chain of command might better understand how their actions could have significant consequences for international security and peace. Nuclear decision-making is shaped by, and interacts with, the ever-changing international security environment and nuclear weapons policy. Tackling problems in the nuclear weapons policy field requires the implementation of ‘system of systems’ design principles, mathematical modelling approaches and multidisciplinary analysis. This research paper presents nuclear weapons decision-making as a complex endeavour, with individual decisions being influenced by multiple factors such as reasoning, intuition (gut feeling), biases and system-level noise. At a time of crisis, these factors may combine to cause risks of escalation. The authors draw on past examples of near nuclear use to examine decision-making in the nuclear context as a ‘wicked problem’, with multi-layered, interacting and constantly fluctuating elements.
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Alexander, Serena E., Mariela Alfonzo, and Kevin Lee. Safeguarding Equity in Off-Site Vehicle Miles Traveled (VMT) Mitigation in California. Mineta Transportation Institute, November 2021. http://dx.doi.org/10.31979/mti.2021.2027.
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Historically, the State of California assessed the environmental impacts of proposed developments based on how it was projected to affect an area’s level of service (LOS). However, as LOS focused on traffic delays, many agencies simply widened roads, which was an ineffective way to reduce greenhouse gas emissions (GHGs). With the passage of Senate Bill (SB)743 in 2013, LOS was replaced by Vehicle Miles Traveled (VMT) as a more appropriate metric by which to gauge the environmental impacts of proposed development. Additionally, SB 743 presented an opportunity for off-site VMT mitigation strategies through banking and exchanges– allowing multiple development projects to fund a variety of strategies to reduce VMT elsewhere in the city or region. While the shift from LOS to VMT has generally been lauded, concerns remain about how to apply SB 743 effectively and equitably. This study aimed to: 1) understand how local governments are addressing this shift toward VMT while ensuring equity, including its approaches to off-site VMT mitigation; and 2) evaluate the various built environment factors that impact VMT, which should be considered by local governments, using both qualitative and quantitative research designs. The study posited that both micro and macro level aspects of the built environment needed to be considered when evaluating the impacts of proposed development on VMT, not only to ensure higher accuracy VMT models, but also because of the potential equity implications of off-site mitigation measures. Using multiple linear regression, the study shows that macroscale built environment features such as land use, density, housing, and employment access have a statistically significant impact on reducing VMT (35%), along with transit access (15%), microscale features such as sidewalks, benches, and trees (13%), and income (6%). More notably, a four-way interaction was detected, indicating that VMT is dependent on the combination of macro and micro level built environment features, public transit access, and income. Additionally, qualitative interviews indicate that transportation practitioners deal with three types of challenges in the transition to VMT impact mitigation: the lack of reliable, standardized VMT measure and evaluation tools; the lack of a strong legal foundation for VMT as a component of the California Environmental Quality Act (CEQA); and the challenge of distributing off-site VMT mitigation equitably. Overall, findings support a nuanced, multi-factor understanding of the context in which new developments are being proposed, both in terms of modeling VMT, but also when considering whether offsite mitigation would be appropriate. The results of this study can help California ensure equitable VMT mitigation that better aligns with the state’s climate goals.