Дисертації: "Model of dynamics of the economic system"

1

Toni. "Economic model of mine closure and its potential for economic transformation." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2015. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-162978.

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In Indonesia, the various mining commodities and the amount of resources and reserves are promising, as evidence there are numerous large-scale mining companies and small-scale mines in operation. In 2014 there were 41 companies that held the CoW (mineral contract of work) and 13 companies active in production; and 76 CCoW (coal contract of work) holders, and 57 companies active in production. As well as this, there are more than a thousand small-scale mining companies active for mining commodities. However, mining commodities provide a resource that is not renewable. This will potentially lead to prolonged problems when mining companies do not adhere to good mining practices, particularly in the closing stages of the mine. Mine closure is the final stage in the process of mining activity. In certain circumstances, closure activities can take a long time and of course can have huge costs. In fact, at this stage, the company is no longer making profit, only incurring costs for the project closure. To prevent problems that may arise after the mine is closed, such as abandoned post-mining land, and the bankruptcy of the company at the end of mining operations, etc., then through specific rules, ie rules of the Minister of Energy and Mineral Resources No. 18 of 2008, the mining company in Indonesia must provide a certain amount of money as a financial guarantee to finance the planned closure project; it must be approved by the government before entering this phase. However, problems are encountered in practice. The government may become overloaded because they have to quickly make a decision on the closure plan submitted by the company. So a tool is needed that can be used to assess the feasibility as soon as the mine closure plan is proposed by a company, these tools can provide an overview and a variety of options for decision making. In this dissertation methodology was developed to create a systems dynamic model of mine closure. The model developed can be applied to a variety of mining methods and for various mining commodities. The model can be used to determine the closure costs, to choose the closure project-financing scenario, and up to micro and macro economic analysis of mining activities in the region. In the case studies conducted in this dissertation, the best scenario of the mine closure planning is to include the everlasting fund in the form of time deposits, and convert the post-mining land for agriculture. The amount of deposit money is about USD 358,986,500 should be spare at the end of mine production, and the total of mine closure cost to be approximately USD 440,757,384. Agriculture, the economic sector as a substitute for the mining sector, the added value to the GRDP (Gross Regional Domestic Product) is about 0.25 % / a for the province, and 1.68 % for the regency, but the contribution of the mining sector to GRDP was 30% / a at province scale, and 90% / a at regency scale. So that the substitution value is less significant to GRDP growth. However, this scenario is the best scenario among others, due to consideration is the certainty of ecological and economic sustainability. it is the best goal of corporate social responsibility to the environment in the post- mining land.

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2

Erdogan, Ezgi. "A Complex Dynamical Systems Model Of Education, Research, Employment, And Sustainable Human Development." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/3/12612138/index.pdf.

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Economic events of this era reflect the fact that the value of information and technology has surpassed the value of physical production. This motivates countries to focus on increasing the education levels of citizens. However, policy making about education system and its returns requires dynamical analyses in order to be sustainable. The study aims to investigate the dynamic characteristics of a country-wide education system, in particular, that of Turkey. System Dynamics modeling, which is one of the most commonly referred tools for understanding the complex social structures, is used. Our model introduces dynamic relationships among different classes of labor forces with varying education levels, university admissions, research quality, and the investments made in education, research and other sectors. Model experimentation provides new insights into the investment and capacity-related aspects of the education system environment.

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3

Reda, Hussein Murad Ali. "A theory for national industrial development presented in a system dynamics model." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/76481.

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The dissertation presents a system dynamics model for national industrial development in developing economies. A development system is defined by national boundary, components and activities. The system is represented by ten activity sectors grouped into three functional classes: (1) Two driving sectors comprising population and investment capital sectors; (2) Seven industrial sectors: resources, manufacturing, agriculture, physical infrastructure, services, technology, and social infrastructure; and (3) An outlet sector represented by a trade sector. The model's general theory of industrial development dynamics is described by causal feedback loops. A causal feedback loop consists of two or more interrelated variables where a change in one of the loop's variables causes all others to change as well. The industrial development model's specific structure evolved by applying the causal feedback theory to the system activity sectors. The model is written in DYNAMO, a continuous system, computer simulation language. A prototype model run illustrated the basic development process and possible effects of alternative policies. Several conclusions were drawn regarding sensitive system parameters and various development policies. In addition, three developing-country examples representing low, middle, and high income groups were evaluated. Recommendations about model use and system analysis were presented. The industrial development model is intended to aid during development analysis and planning phases.
Ph. D.

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4

Metzig, Cornelia. "A Model for a complex economic system." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENS038/document.

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Cette thèse s'inscrit dans le cadre de systèmes complexes appliqués aux systèmes économiques. Dans cette thèse, un modèle multi-agent a été proposé, qui modélise le cycle de production. Il est consitué d'entreprises, ouvirers/foyers, et une banque, et repecte la conservation de la monnaie. Son hypothèse centrale est que les entreprises se basent sur une marge espérée pour déterminer leur production. Un scénario simple de ce modèle, ou les marges espérées sont homogènes, a été analysé dans le cadre de models de croissance stochastique. Les résultats sont la distribution de tailles d'entreprises rassemblant des lois de puissance, et leur distribution du taux de croissance de forme 'tente', ainsi qu'une dépendence de taille de la variance de la croissance. Ces résultats sont proches aux faits stylisés issus d'études empiriques. Dans un scénario plus complet, le modèle contient des caractéristiques supplémentaires: des marges espérées hétérogèges, ainsi que des paiements d'intérêts, la possibilité de faire faillite. Cela ramène le modèle aux modèles macro-économiques multi-agents. Les extensions sont décrites de façon théorique par des équations de replicateur. Les résultats nouveaux sont la distribution d'age d'entreprises actives, la distribution de leur taux de profit, la distribution de dette, des statistiques sur les faillites, et des cycles de vie caractéristiques. Tout ces résultats sont qualitativement en accord avec des résultats d'études empiriques de plusieurs pays.Le modèle proposé génère des résultats prometteurs, en respectant le principe que des résultats qui apparaissent simultanément peuvent soit etre générés par un même processus, soit par plusieurs aui qui sont compatibles
The thesis is in the field of complex systems, applied to an economic system. In this thesis, an agent-based model has been proposed to model the production cycle. It comprises firms, workers, and a bank, and respects stock-flow consistency. Its central assumption is that firms plan their production based on an expected profit margin. A simple scenario of the model, where the expected profit margin is the same for all firms, has been analyzed in the context of simple stochastic growth models. Results are a firms' size distribution close to a power law, and tent-shaped growth rate distribution, and a growth rate variance scaling with firm size. These results are close to empirically found stylized facts. In a more comprehensive version, the model contains additional features: heterogeneous profits margins, as well as interest payments and the possibility of bankruptcy. This relates the model to agent-based macroeconomic models. The extensions are described theoretically theoretically with replicator dynamics. New results are the age distribution of active firms, their profit rate distribution, debt distribution, bankruptcy statistics, as well as typical life cycles of firms, which are all qualitatively in agreement with studies of firms databases of various countries.The proposed model yields promising results by respecting the principle that jointly found results may be generated by the same process, or by several ones which are compatible

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5

Neugebauer, Felix Sebastian. "Tayloring Brazil: a system dynamics model for monetary policy feedback." reponame:Repositório Institucional do FGV, 2011. http://hdl.handle.net/10438/9098.

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The thesis introduces a system dynamics Taylor rule model of new Keynesian nature for monetary policy feedback in Brazil. The nonlinear Taylor rule for interest rate changes con-siders gaps and dynamics of GDP growth and inflation. The model closely tracks the 2004 to 2011 business cycle and outlines the endogenous feedback between the real interest rate, GDP growth and inflation. The model identifies a high degree of endogenous feedback for monetary policy and inflation, while GDP growth remains highly exposed to exogenous eco-nomic conditions. The results also show that the majority of the monetary policy moves during the sample period was related to GDP growth, despite higher coefficients of inflation parameters in the Taylor rule. This observation challenges the intuition that inflation target-ing leads to a dominance of monetary policy moves with respect to inflation. Furthermore, the results suggest that backward looking price-setting with respect to GDP growth has been the dominant driver of inflation. Moreover, simulation exercises highlight the effects of the new BCB strategy initiated in August 2011 and also consider recession and inflation avoid-ance versions of the Taylor rule. In methodological terms, the Taylor rule model highlights the advantages of system dynamics with respect to nonlinear policies and to the stock-and-flow approach. In total, the strong historical fit and some counterintuitive observations of the Taylor rule model call for an application of the model to other economies.

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6

Kellie-Smith, Owen. "Relating forced climate change to natural variability and emergent dynamics of the climate-economy system." Thesis, University of Exeter, 2010. http://hdl.handle.net/10036/115194.

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This thesis is in two parts. The first part considers a theoretical relationship between the natural variability of a stochastic model and its response to a small change in forcing. Over a large enough scale, both the real climate and a climate model are characterised as stochastic dynamical systems. The dynamics of the systems are encoded in the probabilities that the systems move from one state into another. When the systems’ states are discretised and listed, then transition matrices of all these transition probabilities may be formed. The responses of the systems to a small change in forcing are expanded in terms of the eigenfunctions and eigenvalues of the Fokker-Planck equations governing the systems’ transition densities, which may be estimated from the eigenvalues and eigenvectors of the transition matrices. Smoothing the data with a Gaussian kernel improves the estimate of the eigenfunctions, but not the eigenvalues. The significance of differences in two systems’ eigenvalues and eigenfunctions is considered. Three time series from HadCM3 are compared with corresponding series from ERA-40 and the eigenvalues derived from the three pairs of series differ significantly. The second part analyses a model of the coupled climate-economic system, which suggests that the pace of economic growth needs to be reduced and the resilience to climate change needs to be increased in order to avoid a collapse of the human economy. The model condenses the climate-economic system into just three variables: a measure of human wealth, the associated accumulation of greenhouse gases, and the consequent level of global warming. Global warming is assumed to dictate the pace of economic growth. Depending on the sensitivity of economic growth to global warming, the model climate-economy system either reaches an equilibrium or oscillates in century-scale booms and busts.

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7

Vischio, Andrew Joseph. "An analysis of methodologies to estimate the economic impacts of freight transportation system disruptions." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37284.

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Disruptions to the freight transportation system are costly due to freight's critical relationship to economic productivity. This research will analyze the current methods of estimating the economic impacts of disruptions to the freight transportation system. A review of existing literature will be conducted with the intent of finding methods that address different types of disruptions and impacts. Due to varying economic scopes and disruptions studied, the results will likely indicate a broad range of methodologies and trends. The results will be used to better understand the different approaches taken when quantifying the economic impacts of disruptions and therefore enable more informed policy, regulation and investment.

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8

Mojica, Velazquez Jose Luis. "A Dynamic Optimization Framework with Model Predictive Control Elements for Long Term Planning of Capacity Investments in a District Energy System." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3886.

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The capacity expansion of a district heating system is studied with the objective of evaluating the investment decision timing and type of capacity expansion. District energy is an energy generation system that provides energy, such as heat and electricity, generated at central locations and distributed to the surrounding area. The study develops an optimization framework to find the optimal investment schedule over a 30 year horizon with the options of investing in traditional heating sources (boilers) or a next-generation combined heat and power (CHP) plant that can provide heat and electricity. In district energy systems, the investment decision on the capacity and type of system is dependent on demand-side requirements, energy prices, and environmental costs. The main contribution of this work is to formulate the capacity planning over a time horizon asa dynamic optimal control problem. In this way, an initial system configuration can be modified by a 'controller' that optimally applies control actions that drive the system from an initial state to an optimal state. The optimal control is a model predictive control (MPC) formulation that not only provides the timing and size of the capacity investment, but also guidance on the mode of operation that meets optimal economic objectives with the given capacity.

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9

Merz, Laura. "AUTOMATION-INDUCED RESHORING: An Agent-based Model of the German Manufacturing Industry." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-394212.

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The concept of ‘Industry 4.0’ signalises the rise of innovative manufacturing technologies, including industrial robots. Wider applicability of robotic automation and higher efficiency of production processes shift the profitability analysis of strategic relocation decisions. Despite the technological feasibility, diffusion of technology lowers the profitability threshold for robots. Consequently, competitive labour cost advantages, formerly motivating manufacturing firms to offshore production become less relevant. In fact, robots additionally gain importance in the case of shifted global economic realities, such as stricter environmental regulation on global trade and the convergence of the global wage gap. However, the heterogeneous levels of automation among manufacturing firms have not been taken into account when studying the macroeconomic phenomenon of reshoring. This study adds novelty by offering an agent-based perspective which has allowed insights on how the behaviour of firms, guided by simple economic rules on the micro-level, is dynamically influenced by their complex environment in regard to relocation, decision-making hypotheses. Testing various variables sensitive to initial conditions, increased environmental regulations targeting global trade and upward shifting wage levels in formerly offshore production locations have shown to be driving and inhibiting mechanisms of this socio-technical system. Therefore, the dynamic demonstrates a shift from predominantly cited economic reasoning for relocation strategies towards sustainability aspects, pressingly changing these realities on an environmental and social dimension. The popular debate is driven by increased environmental awareness and the proclaimed fear of robots killing jobs. In view of reshoring shaping the political agenda, interest in the phenomenon has recently been fuelled by the rise of populism and protectionism claiming to “bring jobs back home”.

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10

Ревякін, Г. В. "Закономірності циклічного розвитку глобальної економічної системи (автореферат)". Thesis, ХНУ імені В. Н. Каразіна, 2018. http://dspace.univer.kharkov.ua/handle/123456789/14175.

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Дисертація присвячена поглибленню теоретико-методичних засад дослідження особливостей циклічного розвитку глобальної економічної системи та стабілізації економічного розвитку України. Досліджено наукове підґрунтя та охарактеризовано закономірності існування економічних циклів. Удосконалено поняття економічного циклу, який запропоновано розуміти як особливий тип періодичних коливань економічної активності навколо довгострокового тренду, що були викликані особливостями функціонування власне економічної системи та низкою зовнішніх чинників, які виявляються у волатильній природі більшості макроекономічних показників. Розроблено й обґрунтовано товарно-орієнтований підхід до природи економічних циклів, що базується на життєвому циклі товарів, які обертаються на ринку. У межах цього підходу стадії життєвого циклу товару ототожнюються з фазами економічного циклу. Таким чином, нині відомі економічні цикли з різним періодом відповідають життєвому циклу товарів з аналогічним періодом їх обертання на ринку. Розроблено модель динаміки економічної системи, що складається з моделі економічного зростання Р. Солоу та циклічної складової, яка об’єднує економічні цикли різної періодичності. На базі моделі запропоновано алгоритм прогнозування економічної динаміки з урахуванням економічних циклів, методологічною основою якого є метод «сірого ящика», згідно з яким економічний тренд виступає як визначена (невідома) складова, а економічні цикли є предметом вивчення моделі. Практичне застосування алгоритму прогнозування побудовано на використанні фільтра Ходріка-Прескотта як методу детрендизації й швидкого перетворення Фур’є як методу спектрального аналізу циклічної складової. За допомогою запропонованої моделі циклічної динаміки економічних систем проаналізовано динаміку світового ВВП у період 1960-2016 рр., а також складено прогноз до 2021 р. Доведено, що динаміка розвитку світової економіки протягом періоду дослідження мала циклічний характер із явно вираженим 16річним циклом. Циклічність економічної активності простежується в таких макроекономічних показниках, як темпи зростання ВВП, темпи інфляції, рівень безробіття, а також рівень іноземних прямих інвестицій. Завдяки запропонованій моделі циклічної динаміки економічних систем виявлено 8-річні цикли в динаміці прямих іноземних інвестицій та динаміці угод зі злиття й поглинання, які активізуються в точках екстремуму економічного циклу. За результатами дослідження виявлено закономірності протікання економічних циклів у межах глобальної економічної системи: економічні цикли в розвинених країнах мають випереджальний характер стосовно країн, що розвиваються; амплітуда економічних коливань навколо довгострокового тренду в країнах, що розвиваються, в 1,9 раз більша, ніж у розвинених країнах; високі темпи економічного зростання відповідають більшому ступеню волатильності темпів економічного розвитку; міжнародна торгівля відіграє головну роль у синхронізації економічних процесів у масштабі глобальної економічної системи; динаміка чистого експорту й поточного рахунка платіжного балансу в розвинених країнах і країнах, що розвиваються, має зворотно пропорційний характер; динаміка прямих іноземних інвестицій тісно корелює з фазами економічних циклів. Визначено головну мету економічної політики держави, якою слід вважати забезпечення динамічної стійкості, що передбачає підтримання стабільних показників економічного зростання в заданих межах. Для досягнення стабільності економічного розвитку державне регулювання економіки має базуватися на основі дії вбудованих стабілізаторів, до яких ми відносимо автоматичну зміну податкових надходжень і платежів залежно від фази економічного циклу. Розроблено економетричну модель динаміки економічного зростання України на базі моделей класу ARIMA, що розкриває сутність особливостей протікання економічних циклів у національній економіці України на сучасному етапі, а також чинники, що визначають параметри економічних циклів у національному масштабі. Визначено організаційно-економічні засади підвищення рівня міжнародної конкурентоспроможності України в контексті її адаптації до нестабільного глобального економічного простору з метою мінімізації негативних чинників циклічності розвитку глобальної економічної системи та прискорення динаміки економічного зростання. Ключові слова: глобальна економічна система, світова економіка, економічний цикл, цикл ділової активності, циклічність економічного розвитку, економічна криза, канали синхронізації економічних процесів, модель динаміки економічної системи, антициклічна економічна політика. The dissertation for a Candidate Degree in Economics. Speciality 08.00.02 – World Economy and International Economic Relations. – V.N. Karazin Kharkiv National University, Ministry of Education and Science of Ukraine, Kharkiv, 2018. The dissertation provides a deeper theoretical and methodological grounding for the studies of global economic system cyclical development and stability of Ukrainian economic development. The study examined scientific arguments and characterized the patterns of existing economic cycles. As a result of combination of the groups of theories, the definition of economic cycle was refined and put forward as a special type of periodic fluctuations in economic activity around the long-term trend, caused by internal features of the economic system and by a set of external factors that manifest themselves through volatility of most macroeconomic indicators. The dissertation proposes a new product based approach to the study of economic cycles, which considers life-cycle of goods circulating in the market. Within this approach, the product life-cycle stages are identified with the phases of economic cycle. On this ground, the well-known economic cycles of different periods correspond to the life-cycle of goods with a similar period of circulation in the market. The results of this study construct a model of economic system dynamics, which consists from R. Solow economic growth model and cyclical component that includes economic cycles with different periodicity. Based on this model, an algorithm for predicting economic performance that takes into account economic cycles was developed. This algorithm is based on the grey box method, according to which the economic trend is a predefined component, and economic cycles become the subject of the model study. Practical application of the prediction algorithm is based on the Hodrick-Prescott filter as a method of detrending and Fast Fourier Transform as a method of spectral analysis of the cyclic component. With the help of the proposed model of economic system cyclical performance, the dynamics of world GDP in the period between 1960-2016 was analysed, and a forecast was made up to 2021. It is argued then that the world economy development performance during the period viewed contains a prominent 16-year long cycle. The cyclic features of economic activity were traced in such macroeconomic indicators as GDP growth rate, inflation rate, unemployment rate, as well as the amount of foreign direct investment. On the basis of the proposed model of cyclical economic system dynamics, we can define 8-year long cycles in foreign direct investment dynamics and in mergers and acquisitions agreements, triggered at the extremes of the economic cycle. The results of the study revealed certain patterns of economic cycles that take place within the global economic system: economic cycles in developed countries are fast-paced compared to developing countries; the amplitude of economic fluctuations around the long-term trend in developing countries is 1.9 times more than in developed countries; high economic growth rates correspond to high volatility in economic development rates; international trade plays a major role in synchronization of economic processes in the global economic system; net exports and current account balance performance in developed and developing countries are indirectly proportional; foreign direct investment performance is closely related to economic cycle phases. The study also defines the main goal of government economic policy, which needs to ensure dynamic consistency that presupposes stable economic growth within the given frames. To achieve stable economic development, government regulation of the economy should be based on the built-in stabilizers, to which we include automatic change in tax revenues and payments, depending on the business cycle phase. The thesis develops an econometric model of Ukrainian economic growth dynamics based on ARIMA models, revealing the essence of economic cycles in Ukrainian national economy at its present stage, as well as the factors determining parameters of economic cycles on a national scale. Organizational and economic foundations for increasing Ukraine’s international competitiveness with the purpose of adapting to the volatile global economic space, were determined in order to reduce the negative effect of global economic system cyclical development and accelerate the economic growth. Keywords: global economic system, world economy, economic cycle, business cycle, cyclical economic development, economic crisis, economic processes synchronization channels, model of dynamics of the economic system, anti-cyclical economic policy.

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11

Oliveira, Marcel Ferreira de. "Dinâmica da produtividade: uma abordagem por meio de modelo de fatores dinâmicos." Universidade Federal de Juiz de Fora (UFJF), 2015. https://repositorio.ufjf.br/jspui/handle/ufjf/3135.

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O objetivo desta dissertação é estudar a dinâmica da produtividade total dos fatores (PTF) através de um modelo de fatores dinâmicos e verificar a importância do catch up e outros determinantes da PTF por meio do estimador do GMM Sistêmico, utilizando dados da Penn World Table 9.0 entre 1970 e 2014. Devido à existência de transbordamentos tecnológicos e comércio internacional, é esperado que existam variações comuns entre as produtividades de diferente países. Sendo assim, estimamos um modelo de fatores dinâmicos para as PTFs de um conjunto de países tecnologicamente avançados para capturar esses efeitos. Dessa estimativa fomos capazes de extrair seu fator comum e usá-la como proxy para PTF mundial. Isso nos permite incluir a tendência comum na regressão da PTF e estimar seus efeitos sobre a PTF. Nosso fator comum estimado reflete bem aos principais choques de produtividade que ocorreram no período e a sensibilidade de cada país com relação ao fator comum parece estar negativamente relacionada com o nível de desenvolvimento de cada país – essa correlação parece estar de acordo com o argumento de que há um efeito de catch up na produtividade: países mais distantes da fronteira têm crescimento maior por absorverem mais da tecnologia mundial. Além disso, nossas estimativas para o painel dinâmico estimado utilizando este fator estimado reforça esse resultado.
The purpose of this dissertation is to study the global dynamics of total factor productivity (TFP) through a dynamic factors model and verify the importance of the catch up effect and other determinants of TFP through the System GMM estimator, using data from the Penn World Table 9.0 from 1970 to 2014. Because there’re technological spillovers and international trade, it would be expected to see the existence of common variations in the productivity of different countries. Therefore, we apply a dynamic factor model to these productivities and its growth rates in order to capture these effects. These estimates allow us to extract the common factor and use it as a proxy for the world TFP. It allows us to include the common trend in the dynamic equation in the TFP regression in order to estimate its effects on the TFP. Our estimated common factor captures well the main productivity shocks that occurred in the period, and the sensibility of each country to the common factor seems to be negatively related to its country level of technological development – this correlation is in accordance with the argument that there’s a catch up effect in productivity: countries more distant from the frontier have higher growth rates because there is more room to absorb from the global technology. Moreover, our estimates for the dynamic panel using this estimated factor reinforces this result.

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Sánchez, Sánchez Almudena. "Modelling the evolution dynamics of the academic performance in high school in Spain. Probabilistic predictions of future trends and their economical consequences." Doctoral thesis, Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/32280.

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En esta tesis, se utilizan t ecnicas matem atico-epidemiol ogicas para modelar el rendimiento acad emico en Espa~na (prestando especial atenci on en el fracaso escolar) para comprender mejor los mecanismos detr as de esta importante cuesti on, as como para predecir c omo evolucionar an los resultados acad emicos en el Bachillerato espa~nol en los pr oximos a~nos. El nivel educativo de Bachillerato en Espa~na est a formado por los dos ultimos cursos antes de acceder a la universidad o al mercado de trabajo y corresponde a los estudiantes de 16 18 a~nos. Este nivel educativo es muy importante para la formaci on de los estudiantes ya que representa un periodo en el que deber an tomar importantes decisiones sobre el futuro acad emico y profesional. En primer lugar, en el Cap tulo 2, se presenta un modelo determinista donde se analiza el rendimiento acad emico asumiendo que la actitud negativa de los alumnos de Bachillerato puede ser debida a su comportamiento aut onomo y la in uencia de compa~neros con malos resultados acad emicos. Luego, en el Cap tulo 3, se mejora el modelo basado en la idea de que no s olo los malos h abitos acad emicos se transmiten socialmente sino tambi en los buenos h abitos de estudio. Adem as, descomponemos los par ametros de transmisi on de h abitos acad emicos con el n de analizar con m as detalle qu e grupos de estudiantes son m as susceptibles a ser in uenciados por compa~neros con buenos o malos h abitos acad emicos. El abandono escolar tambi en han sido incluido en este modelo. El enfoque adoptado permite proporcionar predicciones deterministas y con intervalos de con anza de la evoluci on del rendimiento escolar (incluyendo las tasas de abandono) en Bachillerato en Espa~na en los pr oximos a~nos. Este enfoque, adem as, nos permite modelar el rendimiento acad emico en otros niveles educativos del sistema acad emico espa~nol o de fuera de Espa~na tal y como se muestra en el Cap tulo 4, donde el modelo se aplica satisfactoriamente al sistema acad emico actual de la regi on alemana de Renania del Norte-Westfalia. Para concluir esta tesis, proporcionamos una estimaci on de los costes relacionados con el rendimiento acad emico espa~nol basado en nuestras predicciones. Esta estimaci on representa la inversi on en Bachillerato por parte del Gobierno espa~nol y las familias en los pr oximos a~nos, con especial atenci on en los grupos de estudiantes que no promocionan y abandonan en los diferentes cursos acad emicos.
In this dissertation, we use epidemiologic-mathematical techniques to model the academic performance in Spain (paying special attention on the academic underachievement) to understand better the mechanisms behind this important issue as well as to predict how academic results will evolve in the Spanish Bachillerato over the next few years. The Spanish Bachillerato educational level is made up of the last courses before accessing to the university or to the work market and corresponds to students of 16¿18 years old. This educational level is a milestone in the career training of students because it represents a period to make important decisions about academic and professional future. In a rst step, in the Chapter 2 we will present a deterministic model where academic performance is analyzed assuming the negative attitude of Bachillerato students may be due to their autonomous behavior and the in uence of classmates with bad academic results. Then, in the Chapter 3, the model is improved based on the idea that not only the bad academic habits are socially transmitted but also the good study habits. Besides, we decompose the transmission academic habits into good and bad academic habits, in order to analyze with more detail which group of students are more susceptible to be in uenced by good or bad academic students. The consideration of quantifying the abandon rates is also a new issue dealt with in it. The adopted approach allow to provide both punctual and con dence intervals predictions to the evolution of academic performance (including the abandon rates) in Bachillerato in Spain over the next few years. The adopted approach allows us to model academic performance in academic levels other than Bachillerato and/or beyond the Spanish academic system. This issue is assessed in Chapter 4, where the model is satisfactorily applied to the current academic system of the German region of North Rhine-Westphalia. To conclude this dissertation, we provide an estimation of the cost related to the Spanish academic underachievement based on our predictions. This estimation represents the investment in the Spanish Bachillerato from the Spanish Government and families over the next few years, paying special attention on the groups of students who do not promote and abandon during their corresponding academic year.
Sánchez Sánchez, A. (2013). Modelling the evolution dynamics of the academic performance in high school in Spain. Probabilistic predictions of future trends and their economical consequences [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/32280
TESIS

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Carro, Patiño Adrián. "Individual-based models of collective dynamics in socio-economic systems." Doctoral thesis, Universitat de les Illes Balears, 2016. http://hdl.handle.net/10803/396311.

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The main purpose of this thesis is to contribute to the understanding of how complex collective behaviors emerge in social and economic systems. To this end, we use a combination of mathematical analysis and computational simulations along the lines of the agent- or individual-based modeling paradigm. In particular, we focus on three main topics: opinion dynamics, herding behavior in financial markets, and language competition. Opinion dynamics models focus on the processes of opinion formation within a society consisting of an ensemble of interacting individuals with diverse opinions. One of the main problems addressed by these models is whether these processes of opinion formation will eventually lead to the emergence of a consensus within the society or to the fragmentation of its constituent individuals into different opinion groups. We are interested here in situations where the particular issue under consideration allows for opinions to vary continuously, and thus opinions are modeled as real variables. In particular, we focus on a model consisting of two mechanisms or rules for the evolution of the agents' opinions: a mechanism of social influence, by which two interacting agents reach a compromise at the midpoint opinion, and a mechanism of homophily, by which two agents do only interact if their opinion difference is less than a given threshold value. In this context, we study the influence of the initial distribution of opinions in the asymptotic solution of the model. Financial time series are characterized by a number of stylized facts or non-Gaussian statistical regularities found across a wide range of markets, assets and time periods, such as volatility clustering or fat-tailed distributions of returns. A growing number of contributions based on heterogeneous interacting agents have interpreted these stylized facts as the macroscopic outcome of the diversity among the economic actors, and the interplay and connections between them. In particular, we focus here on a stochastic model of information transmission in financial markets based on a competition between pairwise copying interactions between market agents (herding behavior) and random changes of state (idiosyncratic behavior). On the one hand, we develop a generalization of this herding model accounting for the arrival of information from external sources, and study the influence of this incoming information on the market. On the other hand, we study a network-embedded version of the herding model and focus on the influence of the underlying topology of interactions on the asymptotic behavior of the system. Language competition models address the dynamics of language use in multilingual social systems due to social interactions. The main goal of these models is to distinguish between the interaction mechanisms that lead to the coexistence of different languages and those leading to the extinction of all but one of them. While traditionally conceptualized as a property of the speaker, it has been recently proposed that the use of a language can be more clearly described as a feature of the relationship between two speakers ---a link state--- than as an attribute of the speakers themselves ---a node state---. Inspired by this link-state perspective, we first develop a coevolving model that couples a majority rule dynamics of link states with the evolution of the network topology due to random rewiring of links in a local minority. Finally, we develop a model where the coupled dynamics of language use, as a property of the links between speakers, and language preference, as a property of the speakers themselves, are considered in a fixed network topology.
El propósito principal de esta tesis es el de contribuir a la comprensión del modo en el que comportamientos colectivos complejos emergen en sistemas sociales y económicos. En particular, nos centramos en tres temas principales: dinámica de opiniones, comportamiento gregario en mercados financieros y competición lingüística. Los modelos de dinámica de opiniones se centran en los procesos de formación de opiniones en el seno de una sociedad compuesta por un conjunto de individuos en interacción y con opiniones diversas. Uno de los principales problemas abordados por estos modelos es el de determinar si estos procesos de formación de opiniones llevan a la emergencia de un consenso en la sociedad, o si llevan a la segregación de los individuos en diferentes grupos. Nos interesamos aquí por situaciones en las que el asunto que se discute permite la existencia de un contínuo de opiniones y por tanto las opiniones pueden ser modeladas como variables reales. En particular, nos centramos en un modelo consistente en dos mecanismos para la evolución de las opiniones: un mecanismo de influencia social, por el cual dos agentes interaccionantes llegan a un compromiso en el punto medio entre sus opiniones, y un mecanismo de homofilia, por el cual dos agentes interaccionan únicamente si la diferencia entre sus opiniones es inferior a un cierto umbral. En este contexto, estudiamos la influencia de la distribución inicial de opiniones. Las series temporales financieras están caracterizadas por una serie de hechos estilizados o regularidades estadísticas no gaussianas observadas en un amplio rango de mercados, activos y períodos temporales, como el agrupamiento de la volatilidad o las distribuciones de retornos con colas pesadas. Un número creciente de contribuciones basadas en agentes heterogéneos en interacción han venido a ofrecer una interpretación de estos hechos estilizados como el resultado emergente de la diversidad entre actores económicos y de las interacciones y conexiones entre ellos. En particular, nos centramos aquí en un modelo estocástico de transmisión de información en mercados financieros basado en una competición entre interacciones de copia a pares entre agentes de mercado (comportamiento gregario) y cambios de estado aleatorios (comportamiento idiosincrático). Por un lado, desarrollamos una generalización de este modelo de comportamiento gregario para tener en cuenta la llegada de información desde fuentes externas y estudiamos la influencia de esta información entrante en el mercado. Por otro lado, estudiamos una versión en red del modelo de comportamiento gregario y nos centramos en la influencia de la topología subyacente en el comportamiento asintótico del sistema. Los modelos de competición lingüística abordan la dinámica del uso de lenguas en sistemas sociales multilingües debida a interacciones sociales. El principal objetivo de estos modelos es el de diferenciar entre aquellos mecanismos de interacción que llevan a la coexistencia de diferentes lenguas y aquellos que llevan a la extinción de todas menos una. Aunque tradicionalmente se ha conceptualizado como una propiedad del hablante, recientemente se ha propuesto que el uso de una lengua puede ser más claramente descrito como una propiedad de la relación entre dos hablantes ---un estado del enlace--- que como una propiedad de los hablantes ---un estado del nodo---. Inspirados por esta perspectiva, desarrollamos primero un modelo de coevolución que acopla una dinámica de estados en los enlaces basada en una regla de mayoría con la evolución de la topología de la red debida al re-enlace aleatorio de enlaces en una minoría local. Finalmente, desarrollamos un modelo en el que las dinámicas acopladas de uso de la lengua, como propiedad de los enlaces entre hablantes, y preferencia lingüística, como propiedad de los hablantes mismos, son consideradas en una topología de red fija.

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Filipová, Fuchsová Regina. "Dynamika obchodního modelu v telekomunikacích." Doctoral thesis, Vysoká škola ekonomická v Praze, 2002. http://www.nusl.cz/ntk/nusl-77117.

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This doctoral thesis is focused on the most progressive part of telecommunications nowadays, on Internet governance and Internet domain name system. This field is not only highly interesting, but only very little researched area from the point of view of economics sciences compared to the traditional fields. Recently, the question of Internet governance was highlighted, but it has been neither resolved nor sufficiently discussed so far. The theory does not answer many questions raised by the praxis sufficiently. The aim of the thesis was to describe the branch in detail and to develop an original model, which would characterise the dependency of the number of registrations on other indicators. This doctoral thesis of Regina Filipova Fuchsova brings a detailed analysis of factors influencing the domain name system. This is the first analysis of this art ever, which targets top level domains .cz and .eu. Typology of TLD registries and connection of domain name selection with the company strategy are further new findings. Based on own analysis and case studies, the author concludes, that there is a relatively strong dependency of the number of registered domains under the respective TLD on national economy characteristics and that the model of the relationship of a ccTLD registry and respective government significantly varies in particular countries. This is due to the historical development and national specifics. The author further came to the conclusion, that national and generic TLDs are partially substitutes and partially complements on national markets. It depends on concrete market and the degree of ccTLD liberalisation, because generic TLDs act as substitutes to the country code TLD on not liberalised markets and/or where the ccTLD is rather expensive. As for the liberalised markets, the growth of a ccTLD goes hand in hand with the growth of gTLD and they compete less. National TLDs of the EU countries and the European TLD .eu show the nature of complements according to the statistical analysis. There are significant theoretical and practical contributions of this work because of its wide content and original analysis in this field. The findings can be practically used for registry benchmarking and ideas related to the delegation of new top level domains.

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Egbunike, Chukwudi Muofunanya Uchenna. "A system dynamics mineral exploitation model." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/38295.

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Warren, Kimber Derek. "System dynamics modelling of strategic responses to exogenous change in the U.K. brewing industry." Thesis, London Business School (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244660.

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Liu, Fuping. "A system dynamics model for hydropower generation planning." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2002. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ62782.pdf.

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Jootar, Jay 1975. "A risk dynamics model of complex system development." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8480.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Sloan School of Management, 2002.
Includes bibliographical references (p. 201-204).
The development of complex systems is a challenging endeavor which has captured the attentions of scholars and practitioners alike. Throughout the decades, numerous methods have been proposed to help manage such development efforts more effectively and efficiently. Some of these methods, such as prototyping, concurrent engineering, iterative model for software development, and system-focused development for R&D, are process models which recommend better ways to structure the development process to handle the complexity of the system under development. This thesis seeks to understand the complex system development from a risk perspective. Continuing from the work done by other researchers, this work combines issues which are traditionally considered separately into one single model. More specifically, the model explicitly captures the dependencies in the system and the structure of an iterative development process and their interactions. The resulting mathematical problem demonstrates the risk characteristics of a development process. It shows that the optimality calls for a trade-off between the reduction of the probability of risk and the increase in the impact of risk. From its structure, the model also helps us understand how different aspects of system architecture affect the structure and the performance of the development process. In addition, the model also reveals the fundamental problems of process models and proposes a generic risk-based alternative. To explore the applicability of the model, the thesis also provides a case study in a software development process and a set of heuristics for solving the resulting combinatorial problem.
by Jay Jootar.
Ph.D.

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Tan, HockWoo. "Agent-based model and system dynamics model for peace-keeping operations." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/44010.

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Approved for public release; distribution is unlimited
Military operations other than war (MOOTW) make up a large percentage of total military operations. Some common MOOTW operations are peacekeeping (PKO) and humanitarian assistance, and disaster relief (HADR). System dynamics (SD) uses a top-down approach that models high-level system behavior as compared to the use of agent-based modeling (ABM), which uses a bottom-up approach to generate system-level behavior through emergent behavior. In this work, SD and ABM were applied to model a food distribution scenario during the early phases of PK/HADR and the implementation process and results compared. The results were that large variations in food prices were observed as the time step and the integration technique were varied. Both SD and ABM, however, displayed similar emergent behavior in terms of crimes that occurred due to relative deprivation within the population. As an alternative to time step approximation, discrete event simulation (DES) may be used to implement the SD model through discretization of stocks or flows within the system and identifying events that change these quantities. The quantization of continuous variables in SD into discrete quantities may, however, introduce quantization errors. Emergent behavior seen in ABM can occur in SD through the interactions between equations. Due to the compactness of SD equations, it feels less intuitive to develop models using SD than it does to develop models using ABM.

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Sontamino, Phongpat. "Decision support system of coal mine planning using system dynamics model." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2015. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-159919.

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Coal is a fossil fuel mineral, which is presently a major source of electricity and energy to industries. From past to present, there are many coal reserves around the world and large scale coal mining operates in various areas such as the USA, Russia, China, Australia, India, and Germany, etc. Thailand’s coal resources can be found in many areas; there are lignite mining in the north of Thailand, the currently operational Mae Moh Lignite Mine, and also coal reserves in the south of Thailand, such as Krabi and Songkhla, where mines are not yet operating. The main consumption of coal is in electricity production, which increases annually. In 2019, the Thai Government and Electricity Generating Authority of Thailand (EGAT) plans to run a 800 MW coal power plant at Krabi, which may run on imported coal, despite there being reserves of lignite at Krabi; the use of domestic coal is a last option because of social and environmental concerns about the effects of coal mining. There is a modern trend in mining projects, the responsibility of mining should cover not only the mining activity, but the social and environmental protection and mine closure activities which follow. Thus, the costs and decisions taken on by the mining company are increasingly complicated. To reach a decision on investment in a mining project is not easy; it is a complex process in which all variables are connected. Particularly, the responsibility of coal mining companies to society and the environment is a new topic. Thus, a tool to help to recognize and generate information for decision making is in demand and very important. In this thesis, the system dynamics model of coal mine planning is made by using Vensim Software and specifically designed to encompass many variables during the period of mining activity until the mine closure period. The decisions use economic criteria such as Net Present Value (NPV), Net Cash Flow (NCF), Payback Period (PP), and Internal Rate of Return (IRR), etc. Consequently, the development of the decision support system of coal mine planning as a tool is proposed. The model structure covers the coal mining area from mine reserves to mine closure. It is a fast and flexible tool to perform sensitivity analysis, and to determine an optimum solution. The model results are clear and easily understandable on whether to accept or reject the coal mine project, which helps coal mining companies make the right decisions on their policies, economics, and the planning of new coal mining projects. Furthermore, the model is used to analyse the case study of the Krabi coal-fired power plant in Thailand, which may possibly use the domestic lignite at Krabi. The scenario simulations clearly show some potential for the use of the domestic lignite. However, the detailed analysis of the Krabi Lignite Mine Project case shows the high possible risks of this project, and that this project is currently not feasible. Thus, the model helps to understand and confirm that the use of domestic lignite in Krabi for the Krabi Coal Power Plant Project is not suitable at this time. Therefore, the best choice is imported coal from other countries for supporting the Krabi Coal Power Plant Project. Finally, this tool successfully is a portable application software, which does not need to be installed on a computer, but can run directly in a folder of the existing application. Furthermore, it supports all versions of Windows OS.

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Pan, Wei Ph D. Massachusetts Institute of Technology. "Reality hedging : social system approach for understanding economic and financial dynamics." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/97971.

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Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 101-112).
This dissertation's main contribution is a new methodology, Reality Hedging, which is to use big-data driven approaches and tools from Computational Social Science for understanding, monitoring and designing economic and financial systems. The center idea in this approach is to treat economic and financial systems as systems of connected people. We are entering a new age where many aspects of our lives are digitized thanks to social media and smart phones. As we see many areas of research topics using these datasets to establish new behavioral and social theories about our society (e.g.: Reality Mining, Social Network Analysis, etc), it is natural to ask if and how we can use these advancements to build better economic and financial structures and institutions especially after the past financial crisis. After all, all economic systems are systems of people, rather than systems of atoms which always follow the same physics principles and mechanism. I collected and analyzed some large economic and financial social systems from individual levels to city levels. Many connections between financial dynamics with social dynamics were examined. I also focus on results and findings that can be used to build resilient and productive economic systems, and can be used to hedge out risks resulting from the social connectivity. In this thesis, I will discuss my research efforts in collecting valuable large-scale behavior data using smart phones. I will show that such datasets are helpful in inferring individual financial status. I will expand individual observations to new models for understanding the innovation economics in cities. I will continue to elaborate the idea of idea flow in behavior changes by focusing on the study of an online trading platform which allows traders to discuss and share trades with each other.
by Wei Pan.
Ph. D.

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Schmidt, Gordon W. "Dynamics of endogenous economic growth : a case study of the "Romer model" /." Amsterdam [u.a.] : Elsevier, 2003. http://www.loc.gov/catdir/enhancements/fy0614/2003043910-d.html.

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Borsati, Mattia. "Empirical Essays on Transport and Regional Economics: Safety, Intermodality, and Commuting Dynamics." Doctoral thesis, Università degli studi di Trento, 2020. http://hdl.handle.net/11572/268170.

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The following doctoral thesis, sponsored by Autostrada del Brennero S.p.A. (an Italian highway concession company in charge of managing toll roads) consists on empirical essays at the crossroad between transport and regional economics. They focus on different aspects that directly involve motorways (i.e, safety, intermodality, and commuting dynamics) and they are aimed at providing further evidences that transport institutions and policy makers could take into account throughout their decision-making processes. The first chapter presents a research article that seeks to determine the impact of an average speed enforcement system in reducing highway accidents. Indeed, at the end of 2005, Autostrade per l'Italia (ASPI) and the Italian traffic police progressively deployed along the Italian tolled motorway network an average speed enforcement system, named Safety Tutor, able to determine the average speed of vehicles over a long section to encourage drivers to comply with speed limits and improve safety. To empirically test the extent to which Safety Tutor led to a reduction in both total and fatal accidents on Italian highways during the period of 2001-2017, we carried out a generalized difference-in-differences estimation using a unique panel dataset that exploits the heterogeneous accident data within all tolled motorway sectors in a quasi-experimental setting. To deal with the potential endogeneity of the non-random placement of Safety Tutor sites, we utilized an instrumental variable strategy by using the network of motorway sectors managed by ASPI and its controlled concessionaires from 2005 onwards (i.e., when the technology was available) as an instrument to predict Safety Tutor adoption. We found that a 10% increase in Safety Tutor coverage led to an average reduction in total accidents of 3.9%, whereas there is no evidence of a significant causal effect of Safety Tutor in reducing fatal accidents. The second chapter presents a research article that seeks to investigate the inter-modal competition between motorway and high-speed rail (HSR) services, as the extent to which HSR demand could be the result of a modal shift from motorways is a relevant issue in any cost-benefit analysis of HSR investments. Indeed, the development of HSR has had a notable impact on modal market shares on the routes on which its services have been implemented. To analyse whether the HSR expansion in Italy has led to a modal shift from motorway to HSR, we empirically test i) whether HSR openings adjacent to motorway sectors have reduced the total km travelled by light vehicles on these sectors during the period 2001-2017; and ii) whether this reduction has been persistent or even more evident after the opening of on-track competition between two HSR operators. To do so, we carried out a generalized difference-in-differences estimation, using a unique panel dataset that exploits the heterogeneous traffic data within all tolled motorway sectors in a quasi-experimental setting. Our findings reveal that neither HSR openings nor the opening of on-track competition led to a modal shift from motorway to HSR services, as the two transport modes are non-competing. Conversely, HSR expansion had a slightly positive impact on motorway traffic. The third chapter presents a data article in a “data in brief” format that describes a dataset on municipality-to-municipality commuting patterns in Italy over the 1991, 2001, and 2011 censuses aimed at investigating the role of transport infrastructures and the structural transformation of the economy on worker mobility. At this purpose, a core origin-destination dataset on the number of workers moving between municipalities, or within the same municipality, has been linked with further municipality covariates on jobs location, population, and the distances in meters and journey times in minutes between all municipalities. Even though these data are freely available online, they require some tedious work to organize. Therefore, this data article brings the necessary information together and makes the dataset available on request. The dataset offers applied researchers an alternative source of information to shed new lights on the changing shape of urban systems by analysing i) the impact of infrastructural endowment in providing better job accessibility, or ii) the connection between increasing commuting patterns and the structural transformation of the economy due to the tertiarization process from 1991 to 2011.

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Mbiti, Titus Kivaa Peter, and tkivaap@yahoo com. "A System Dynamics Model of Construction Output in Kenya." RMIT University. Property Construction & Project Management, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20081211.160910.

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This study investigates fluctuations of construction output, and growth of the output in Kenya. Fluctuation and growth of construction activity are matters of concern in construction industries of many countries in the developing as well as in the developed world. The construction industry of Kenya is therefore an exemplifying case for this phenomenon. Construction activity in Kenya fluctuates excessively and grows very slowly. This remains a big challenge to policy makers, developers, consultants and contractors in their decision-making processes. In this study, systems thinking was applied to investigate the problem of excessive fluctuations and stunted growth of construction output in Kenya. The study developed a system dynamics model to simulate the construction output problem behaviour. The historical behaviour of the construction industry was described using construction output data of a 40-year period - from 1964 to 2003. Line graphs of the historical data exhibited profiles that helped to identify the system archetypes operating in the industry. From the profiles, it was deduced that the problem of fluctuations and slow growth of construction output in Kenya is encapsulated in two system archetypes, namely: balancing process with a delay, and limits to growth. The relationship between construction output and its determinant factors from the constru ction industry's environment was investigated using time series regression, which involved autoregressive integrated moving average (ARIMA) regression and multiple regression modelling of the output. On the basis of the historical data analysis and the system archetypes identified, a system dynamics (SD) model was developed to replicate the problem of fluctuations and slow growth in the construction output. The data used to develop the system dynamics model was annual construction output in Kenya from 1964 to 2003. The model was then used: to appraise policy changes suggested by construction industry participants in Kenya, and to project construction output in Kenya from year 2004 to year 2050, in order to establish the expected future fluctuations and growth trends of the construction output. It was observed that three fundamental changes are necessary in the system structure of the construction industry of Kenya, in order to minimize fluctuations and foster growth in construction output in the country, in the long run. The changes are: setting long-term targets of annual construction output in the industry as a whole, incorporating reserve capacity in the production process, and expanding the system st ructure to capture a larger construction market. The study recommends regulation of the response of the construction industry of Kenya to changes in construction demand in the market, and expansion of the construction industry's market into the African region and beyond.

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25

Yung, Christian Hung Shing. "The privatization process--a system dynamics model for Brazil." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/12086.

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26

Gozluklu, Burak. "A new project management system dynamics model and simulator." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113517.

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Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 56-57).
Simulators generated from project management system dynamics models are exercised for training the future project managers. In today's' high dynamic, vibrant and complex markets, the models should incorporate more business dynamics and also provide more tools to the players who can flexibly steer in the project games. Along with that objective, this study brings new dynamics and modeling approach to the original multi-phase project system dynamics model of Ford and Sterman, 1998. The new dynamics include the development of new features in the market growing the customer expectation, reflection of customer expectation to project economics, supersede of project concurrencies by rushing the tasks, allowing the defects delivered to customers to be compensated by lifetime repair cost and free positioning of the phase schedules while maintaining concurrencies. A new formulation for completion putthrough, option to include final downstream defect correction and elaborate project econometrics are also included. The model is built in modules that can be utilized to increase the number of phases and/or explain the model to the trainees more easily. The project model employs two options; a zero-defect policy and allowed defect policy where the latter is newly introduced by the repair cost. The system dynamics model is tested by proposed extreme project manager traits which are implemented as table function to use one or more modules to pursue an ultimate objective within a certain logic. A construction project principally mimicking the cases provided by Parvan et al. 2015 is simulated with the manager traits. The results initiate interesting tradeoffs such as the influence of project delivery time versus repair cost, accepting new tasks versus creating more defects or rescheduling the project or positioning the workforce before the ramping up of testing and defective task correction activities. The model necessitates a deeper understanding and analyses of long-term phenomenon such as the lifetime repair cost, the financial consequences of defects and lifetime earnings of products as well as the continuous feature development in the market and its economic value. It is found that the current model proposes an enhanced tool for the training of future project managers. Keywords: System dynamics, project management, simulation, defect policy, numerical modeling.
by Burak Gozluklu.
S.M. in Engineering and Management

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27

Quan, Chuanwen. "A system dynamics model for the development of China's air transportation system." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-09182008-063445/.

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Grobbelaar, Sara Susanna. "R&D in the national system of innovation a system dynamics model /." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-07212007-130132.

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29

Soddemann, Thomas. "Non-equilibrium molecular dynamics study of an amphiphilic model system." [S.l. : s.n.], 2001. http://ArchiMeD.uni-mainz.de/pub/2001/0015/diss.pdf.

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30

McNamara, James. "The dynamics of a bushmeat hunting system under social, economic and environmental change." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/24407.

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The trade in bushmeat for human consumption is an important source of income and food for many people in tropical Africa. Yet it also represents one of the most significant threats to the persistence of wildlife. This threat has been exacerbated in recent decades as the trade has become increasingly commercial in nature, and previously pristine habitats have been degraded due to agriculture and extractive industries. These agricultural, production landscapes are increasingly the face of rural Africa, particularly West Africa. Understanding how economic and landscape-level pressures influence hunting behaviour in these production landscapes will be critical to developing effective management policies that are able to address both development and conservation agendas. This study uses a unique 26-year dataset, collected in the Atwemonom market in Kumasi, Ghana, to examine the spatio-temporal dynamics of the bushmeat trade in the region. A multidisciplinary, multi-scale approach is adopted to present a holistic overview of the trade. Four analyses are presented. Firstly, a framework is developed to assess the degree to which the trade is driven by the demands of the consumer, or the behaviour of the hunter. Secondly, an econometric supply and demand model based on available market data is tested and implemented to analyse the drivers of supply and demand in the commercial system. Thirdly, a spatial model is designed to explore how the biophysical characteristics of the landscape influence what is harvested, from where it is harvested and how this has changed over time. Finally, the findings of these three approaches are used to inform a scenario analysis that explores the socioeconomic factors determining a hunter's willingness to adapt their behaviour in light of changing incentives to participate. The findings highlight the importance of the production landscape for supporting the bushmeat trade in the region and present evidence that suggests the trade around Kumasi may be defined more by drivers of supply (hunter behaviour) than demand (consumer preference). This raises concerns about the effectiveness of demand side management. The results emphasise the need for integrated approaches to bushmeat management that consider the full range of social, economic and environmental drivers.

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31

Cao, Shiya. "Analysis of Household Water Filtration in China: A System Dynamics Model." Digital WPI, 2018. https://digitalcommons.wpi.edu/etd-theses/1268.

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As the economy has been growing fast in China, Chinese people have more incomes and then higher standard of living. In the case of household water treatment, more and more urban residents in China use bottled water or water filtration system instead of tap water because people start to worry about polluted tap water. According to a survey from China Water Supply Services Promotion Alliance in 2014, 59% of urban residents drinking water is from tap water (after being boiled), 41% from bottled water and water filtration system. The 41% participants prefer bottled water as the first choice over a water filtration system. The comparative advantages and disadvantages of home water filtration system and bottled water are analyzed using comparative analysis. The reasons why home water filtration industry has grown slowly in urban China even though it is less expensive and has environmental benefits are analyzed using a system dynamics model. The model focuses on the physical system of home water filtration industry. The study shows that order delivery delay and service time are key factors to the adoption rate of home water filtration system. However, initial cost becomes a limiting factor to the growth of the market of home water filtration system. The study proposes the according market policy, demand policy, and supply policy to improve the current scenario.

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32

Rupp, Matthew Y. "Passive dynamic steering system model for use in vehicle dynamics simulation." Connect to resource, 1994. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1157568618.

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Knoll, Karin L. (Karin Lynn). "A system dynamics model for the diffusion of a new technology." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/8957.

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Thesis (S.M.)--Massachusetts Institute of Technology, Sloan School of Management, 1995.
Includes bibliographical references (p. 193-194).
It is often difficult for companies producing new technologies to predict the acceptance pattern (or diffusion pattern) for the new technology in the marketplace. The expected diffusion pattern is important because it affects and is affected by the production, financial, sales and distribution strategies for the new technology, as well as decisions related to marketing and technical development. It is also useful if the projection of technology acceptance offers the firm insight into the factors that drive acceptance and the factors that contribute to rejection of the technology in the marketplace. This thesis develops a system dynamics model for the diffusion of a new medical technology. At the model's core is a general theory of medical technology emergence proposed by Dr. Jack Homer in his 1983 Ph.D. thesis entitled "A Dynamic Model for Analyzing the Emergence of New Medical Technologies." By parameterizing Dr. Homer's general system dynamics model to suit the new technology case, it is hoped that the model will give rise to a greater understanding of the factors relevant to diffusing the technology, as well as lead to more informed managerial decision making as progress is made with the technology.
by Karin L. Knoll.
S.M.

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34

Ahn, Namsung 1955. "A system dynamics model of a large R&D program." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9541.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1999.
Includes bibliographical references (leaf 122).
Organizations with large R&D activities must deal with a hierarchy of decision regarding resource allocation. At the highest level of allocation, the decision is related to the total allocation to R&D as some portion of revenue. The middle level of allocation deals with the allocation among phases of the R&D process. The lowest level of decisions relates to the resource allocation to specific projects within a specific phase. This study focuses on developing an R&D model to deal with the middle level of allocation, i.e., the allocation among phases of research such as basic research, development, and demonstration. The methodology used to develop the R&D model is System Dynamics. Our modeling concept is innovative in representing each phase of R&D as consisting of two parts: projects under way, and an inventory of successful but not-yet-exploited projects. In a simple world, this concept can yield an exact analytical solution for allocation of resources among phases. But in a real world, the concept should be improved by adding more complex structures with nonlinear behaviors. Two particular nonlinear feedbacks are incorporated into the R&D model. The probability of success for any specific project is assumed partly dependent upon resources allocated to the project. Further, the time required to reach a conclusion regarding the success or failure of a project is also assumed dependent upon the level of resources allocated. In addition, the number of successful projects partly depends on the inventory of potential ideas in the previous stage that can be exploited. This model can provide R&D management with insights into the effect of changing allocations to phases whether those changes are internally or externally driven. With this model, it is possible to study the effectiveness of management decisions in a continuous fashion. Managers can predict payoffs for a host of different policies. In addition, as new research results accumulate, a re-assessment of program goals can be implemented easily and allocations adjusted to enhance continuously the likelihood of success, and to optimize payoffs. Finally, this model can give managers a quantitative rationale for program evaluation and permit the quantitative assessment of various externally imposed changes.
by Namsung Ahn.
Ph.D.

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35

Smith, Edwin L. "A system dynamics computer model for long-term water quality planning." Thesis, Virginia Tech, 1985. http://hdl.handle.net/10919/41562.

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The objective of this study was to develop a comprehensive, basin-wide, water-quality-planning model using system dynamics methodology. Later, the model was to be interfaced with a more conventional system dynamics model: one simulating social, technological, economic, and political interactions. By doing so, it is envisioned that such management policies as zoning, abatement facilities, and best management practices may be simulated together.

Master of Science

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36

Kopainsky, Birgit [Verfasser]. "A system dynamics analysis of socio-economic development in lagging Swiss regions / Birgit Kopainsky." Aachen : Shaker, 2005. http://d-nb.info/1181612284/34.

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37

Baker, Elizabeth White. "The Impact of Relational Model Bases on Organizational Decision Making: Cases in E-Commerce and Ecological Economics." VCU Scholars Compass, 2006. http://hdl.handle.net/10156/1399.

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38

Pourmasoumi, Langarudi Saeed. "A System Dynamics Approach to the Political Economy of Resource-dependent Nations." Digital WPI, 2016. https://digitalcommons.wpi.edu/etd-dissertations/432.

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"Development on the basis of extraction and export of natural resources is a dynamically complex problem. Empirical evidence shows that while some nations have been successful to translate natural resource wealth into long-term development but many have failed too. In this dissertation a system dynamics approach is taken to understand why this is happening and what strategies could facilitate a resource-based development process. In this regard, Mashayekhi’s model of oil-dependency of Iranian economy as one of the few relevant system dynamics examples is updated and revalidated. The results show that despite its capability in showing the dynamics of the problem from an economic perspective it lacks socio-political features that are necessary to address the most fundamental issues of resource-based development. It is shown that Katouzian’s theory of “arbitrary state and society” could fill this gap. The theory is, thus, translated into a system dynamics model so that it could be tested for internal consistency and used for policy analysis. The model is able to explain long-term socio-political-economic instability of a resource-dependent society. On the basis of Mashayekhi’s model, Katouzian’s theory, and other fundamental explanations of natural resource dependency that are available from the literature, a generic eclectic model is developed. The model has gone through a comprehensive list of confidence-building tests. Controlled experimentation through Monte Carlo simulations show that, on the contrary to the current belief, it is unlikely that natural resource wealth be harmful for social welfare. Results also revealed that rule of law is a crucial factor that affects trajectory of the socio-political-economic development. Other findings are as follow. Civil resistance (disobedience) can be harmful for the system in the long-run. While sanctions could affect the economy it has barely an impact on socio-political settings of a society. Finally, wage stabilization, facilitation of social mobility, and privatization of natural resource revenues within certain limits) could help the resource-based development to achieve better outcomes."

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Schmidt, Gordon 1946. "Dynamics of endogenous economic growth theory and related issues : a case study of the "Romer model"." Monash University, Dept. of Economics, 2001. http://arrow.monash.edu.au/hdl/1959.1/8832.

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Pfaender, Jens Holger. "Competitive Assessment of Aerospace Systems using System Dynamics." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14014.

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Aircraft design has recently experienced a trend away from performance centric design towards a more balanced approach with increased emphasis on engineering an economically successful system. This approach focuses on bringing forward a comprehensive economic and life-cycle cost analysis, which can be addressed by the introduction of a dynamic method allowing the analysis of the future attractiveness of such a concept in the presence of uncertainty. One way of addressing this is through the use of a competitive market model. However, existing market models do not focus on the dynamics of the market, which results in poor predictive capabilities. The method proposed here focuses on a top-down approach that integrates a competitive model based on work in the field of system dynamics into the aircraft design process. The primary contribution is the demonstration of the feasibility of such integration. This integration is achieved through the use of surrogate models, which enabled not only the practical integration of analysis techniques, but also reduced the computational requirements so that interactive exploration as envisioned is actually possible. An example demonstration of this integration is built on the competition in the 250 seat large commercial aircraft market. Two aircraft models were calibrated to existing performance and certification data and then integrated into the system dynamics market model, which was then calibrated with historical market data. This calibration showed a much improved predictive capability as compared to the conventional logit regression models. The resulting market model was then integrated into a prediction profiler environment with a time variant Monte-Carlo analysis resulting in a unique trade-off environment. This environment was shown to allow interactive trade-off between aircraft design decisions and economic considerations while allowing the exploration potential market success in the light of varying external market conditions and scenarios. Another use of the existing outputs of the Monte-Carlo analysis was then realized by visualizing the model variables on a multivariate scatter plot. This enables the designer to define strategic market and return on investment goals for a number of scenarios and then directly see which specific aircraft designs meet these goals.

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Al-Gobaisi, Darwish M. K. F. "Economic scheduling in electric power systems : a mathematical model for the U.A.E." Thesis, Loughborough University, 1988. https://dspace.lboro.ac.uk/2134/7288.

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42

Beringer, Tim. "Earth system dynamics in the Anthropocen." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2012. http://dx.doi.org/10.18452/16442.

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In nie dagewesener Größenordnung greift der Mensch durch die Verbrennung fossiler Energieträger und der weiträumigen Umgestaltung der Landoberfläche in die globale Umwelt ein. Klimawandel und Übernutzung natürlicher Ressourcen könnten schon in diesem Jahrhundert die Anpassungsfähigkeiten vieler ökologischer und sozialer Systeme übersteigen und somit zu Konflikten und politischer Destabilisierung führen. Vor diesem Hintergrund soll diese Studie zu einem besseren Verständnis der wichtigsten globalen Triebkräfte beitragen, die die Entwicklung der terrestrischen Biosphäre in diesem Jahrhundert prägen werden: Klimawandel und menschliche Landnutzung. Auf der Basis eines Dynamischen Globalen Vegetationsmodells werden im ersten Teil der vorliegenden Arbeit zwei große klimatische Störungen des globalen Kohlenstoffkreislaufs untersucht, die innerhalb der letzten drei Jahrzehnte beobachtet wurden. Im Fordergrund steht die Frage, wie sich die Veränderungen von Temperatur-, Niederschlags- und Strahlungsbedingungen auf pflanzliche Produktivität und Zersetzungsprozesse im Boden auswirkten. Es zeigt sich, dass vermehrte Kohlenstoffspeicherung in der Landbiosphäre den überwiegenden Teil der atmosphärischen CO2 Anomalien erklärt. Der zweite Teil dieser Arbeit beschäftigt sich mit der weltweit steigenden Nachfrage nach Bioenergie, die aufgrund des flächenintensiven Anbaus von Biomasse zur wichtigsten Triebkraft für zukünftige Landnutzungsänderungen werden könnte. Aus der Kombination von Vegetationsmodellierung und räumlichen Datenanalysen werden globale Bioenergiepotentiale unter Berücksichtigung verschiedener Nachhaltigkeitsanforderungen bestimmt und mögliche ökologische Auswirkungen des großräumigen Anbaus von Energiepflanzen abgeschätzt. Im Jahr 2050 könnten demnach 15-25% des weltweiten Energiebedarfs durch Bioenergie abgedeckt werden. Dafür müssten allerdings natürliche Ökosysteme in großem Umfang in Agrarland umgewandelt werden.
Human activities, primarily the combustion of fossil fuels and the global modification of the land surface, are transforming the Earth System at unprecedented scale. Climate change and the overexploitation of natural resources may soon overwhelm the adaptive capacities of many ecosystems and societies, which could lead to substantial losses in human well-being and political destabilization. In this context, it is the goal of this thesis to contribute to a better understanding of the most important global drivers that will determine the future of the land biosphere during this century: climate change and human land use. Based on a Dynamic Global Vegetation Model (DGVM), the first part of this thesis examines two large climatic disturbances of the terrestrial carbon cycle that were observed during the last three decades. These analyses focus on the effects of changes in temperature, precipitation and radiation on plant productivity and soil decomposition. Results indicate that increased carbon storage in the land biosphere explains the most part of the atmospheric CO2 anomaly. The second part of this thesis addresses the worldwide increasing demand for bioenergy that may become the most important driver of future land use change due to the large area requirements of biomass cultivation. A combination of vegetation modeling and spatial data analyses is used to assess global bioenergy potentials that consider various sustainability requirements for food security, biodiversity protection and the reduction of greenhouse gas emissions and to evaluate the environmental impacts of large-scale energy crop cultivation. The results indicate that bioenergy may provide between 15 and 25% of the global energy demand in 2050. Exploiting these potentials, however, requires the conversion of large amounts of natural vegetation into agricultural land affecting a large number of ecosystems already fragmented and degraded by land use change.

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43

Burtt, Kelly D. "Computational studies of photo-induces isomerization dynamics in a model molecular motor system." abstract and full text PDF (free order & download UNR users only), 2005. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3209954.

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44

Toni. "Economic model of mine closure and its potential for economic transformation." Doctoral thesis, 2014. https://tubaf.qucosa.de/id/qucosa%3A22975.

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Анотація:

In Indonesia, the various mining commodities and the amount of resources and reserves are promising, as evidence there are numerous large-scale mining companies and small-scale mines in operation. In 2014 there were 41 companies that held the CoW (mineral contract of work) and 13 companies active in production; and 76 CCoW (coal contract of work) holders, and 57 companies active in production. As well as this, there are more than a thousand small-scale mining companies active for mining commodities. However, mining commodities provide a resource that is not renewable. This will potentially lead to prolonged problems when mining companies do not adhere to good mining practices, particularly in the closing stages of the mine. Mine closure is the final stage in the process of mining activity. In certain circumstances, closure activities can take a long time and of course can have huge costs. In fact, at this stage, the company is no longer making profit, only incurring costs for the project closure. To prevent problems that may arise after the mine is closed, such as abandoned post-mining land, and the bankruptcy of the company at the end of mining operations, etc., then through specific rules, ie rules of the Minister of Energy and Mineral Resources No. 18 of 2008, the mining company in Indonesia must provide a certain amount of money as a financial guarantee to finance the planned closure project; it must be approved by the government before entering this phase. However, problems are encountered in practice. The government may become overloaded because they have to quickly make a decision on the closure plan submitted by the company. So a tool is needed that can be used to assess the feasibility as soon as the mine closure plan is proposed by a company, these tools can provide an overview and a variety of options for decision making. In this dissertation methodology was developed to create a systems dynamic model of mine closure. The model developed can be applied to a variety of mining methods and for various mining commodities. The model can be used to determine the closure costs, to choose the closure project-financing scenario, and up to micro and macro economic analysis of mining activities in the region. In the case studies conducted in this dissertation, the best scenario of the mine closure planning is to include the everlasting fund in the form of time deposits, and convert the post-mining land for agriculture. The amount of deposit money is about USD 358,986,500 should be spare at the end of mine production, and the total of mine closure cost to be approximately USD 440,757,384. Agriculture, the economic sector as a substitute for the mining sector, the added value to the GRDP (Gross Regional Domestic Product) is about 0.25 % / a for the province, and 1.68 % for the regency, but the contribution of the mining sector to GRDP was 30% / a at province scale, and 90% / a at regency scale. So that the substitution value is less significant to GRDP growth. However, this scenario is the best scenario among others, due to consideration is the certainty of ecological and economic sustainability. it is the best goal of corporate social responsibility to the environment in the post- mining land.

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45

徐旻業. "A system dynamics model of the development in Western China influence on regional economic." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/22807216575993782274.

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46

Hariharan, R. "System Dynamics Modeling Of Stylized Features Of Stock Markets." Thesis, 2006. http://hdl.handle.net/2005/463.

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The common theme throughout the thesis is to explore the possibility of using a single framework, namely the systems theory framework, in modeling a few stylized features of a financial market. A systems theoretic model is developed, in this thesis in Chapter 3, for confidence bias of an individual. The effect of this bias on his investment decision is brought out explicitly. The phenomenon of excessive trading, arising due to overconfidence and optimism, has been explained. The concept of virtual capital, incorporating the ideas from prospect theory, is introduced. We have proposed a dynamical system framework to model limits to arbitrage and the herding behavior in financial markets in Chapter 4. The market evolves due to the participation of traders. It is instructive to look at the market as a system evolving from a set of initial conditions during every time interval. In the proposed model, herding is defined as a specific relation between the system responses. The proposed herding measure quantifies how far the individual is from clustering with others. It is also shown how this interpretation helps us to understand the effects of herding. There exists a risk when the market price variation, due to herding, is thought of as entirely due to the portfolio fundamentals. The generic dynamical system model that captures some aspects of the limits of arbitrage is also proposed wherein fundamental risk, noise trader risk, implementation risk, and model risk can be incorporated. The proposed model offers a single framework to study the Marginally Efficient Market and Synchronization Risk models. In Chapter 5, we have proposed a switching dynamical system with minority game rules incorporated within the framework. We have explored the possibility of developing a market model, in Chapter 6, in the same framework that has been used to develop models for arbitrage and herding. We have explored, in this thesis, the possibility of using a single framework to model stylized features of stock market. It will be a long way before a single model can capture all complex characteristic features of a stock market. We have attempted, in this thesis, to capture a few stylized features in a single framework, if not in a single model. Different models proposed for individual confidence bias, limits to arbitrage, herding, and switching model for incorporating minority games are all set up in system dynamics framework. This leads to a stage where one can explore incorporating other features, not addressed in this thesis, in system dynamics framework. If each feature is captured using a different framework like confidence bias as stochastic system, herding as pattern cluster, limits to arbitrage as rule-based agents, etc., it would be difficult to integrate them into a single framework. But, in the present work, we have captured the chosen stylized features using system dynamics framework though individual models differ from each other substantially. The challenges are many in creating a single framework. The vision of such framework may involve different components such as modeling decision making, considering risk profiles, devising investment strategies, etc. Stylized features would come as emergent properties of complex interactions among the components of the system. Emergence refers to the way in which multiplicity of simple interactions lead to complex behavior. Emergence of such features may include different time scales of causal relationships among components. System may have thresholds, determined by diversity of traders and nature of interactions, which is vital for features to become emergent. This can be seen in practice. Stock market regulates the relative prices of companies across the world. There is no single central agency to control the workings of the market. Traders have knowledge of only few companies within their portfolio, and to follow transaction rules. Trends and patterns are still emerging which are studied by technical analysts. Emergent properties are mostly signature of self-organizing complex system. Self-organization in complex system relies on four properties which are fundamental in system dynamics framework: positive feedback, negative feedback, multiple interactions, and balance among strategies. A complex adaptive stock market system which is self-organizing and exhibit stylized features as emergent property is a distant goal of system theorists around the world. The challenge does not end there. We have attempted to model and study the stylized features of a stock market in systems theory framework. The focus of our approach is to use the dynamical system modeling to study the features. We have not considered the investment aspects in a financial market. The investment models are very important in real life for individuals and policy-makers. Future extension of the ideas explored in this thesis could be along the lines of creating investment models for individuals and policy-makers. Creating such models using complex adaptive stock market system goes a long way in understanding a phenomenon that had started by Dutch East India Company issuing shares on Amsterdam Stock Exchange way back in 1602.

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47

Hafner, Sarah. "Closing the green finance gap in the UK: policy recommendations and economic implications, using the system dynamics Green Investment Barrier Model (GIBM)." Thesis, 2020. https://arro.anglia.ac.uk/id/eprint/707186/1/Hafner_2020.docx.

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In 2019, the UK pledged to achieve a net-zero carbon emission economy by 2050. While the so-called ‘green finance gap’ is generally acknowledged in this context, tailored policy recommendations on how to address it are missing. The focus of this thesis lies on the upscaling of private finance (e.g. from institutional investors).This thesis builds a new system dynamics energy-economy model – called the Green Investment Barrier Model (GIBM) – that includes as a main novelty the representation of a green finance gap. System dynamics is most appropriate to model complex systems and to understand the likely long-term trends. In terms of key contributions, first the qualitative investigation demonstrates that key investment barriers form a complex system characterised by path dependency, lock-in and non-linearity. Therefore, the adoption of a systems policy, drawing on a long-term and holistic systems perspective and tackling identified key green investment barriers is recommended to close the green finance gap. Second, in terms of modelling contributions and as shown by GIBM, when a green finance gap exists, the introduction of a finance systems policy leads to multiple co-benefits, including an emission reduction, a decline in unemployment and a drop in the unit costs of energy, while increasing GDP by 2050. Further, GIBM results reveal that reaching the UK zero carbon targets for the electricity sector by 2050 requires the implementation of additional low-carbon energy policies besides a finance system policy. Finally in terms of modelling results, the recommended energy policy scenario includes a step-wise linear halt in brown energy infrastructure until 2050. Co-benefits of this latter policy scenario include higher GDP, lower energy system costs and lower unemployment. Third, in terms of theoretical contributions, it is demonstrated that the theoretical underpinning of models influences not only the magnitude of the impact but also the sign of their results and consequently policy formulation, it is therefore argued that more transparency on this among policy-makers is required, along with increased knowledge on how models with different theoretical frameworks should or should not be applied in combination.

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Vortkamp, Irina. "Biological conservation: mathematical models from an ecological and socio-economic systems perspective." Doctoral thesis, 2021. https://repositorium.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-202110015459.

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Conservation in the EU and all over the world aims at reducing biodiversity loss which has become a great issue in the last decades. However, despite existing efforts, Earth is assumed to face a sixth mass extinction. One major challenge for conservation is to reconcile the targets with conflicting interests, e.g. for food production in intensively used agricultural landscapes. Agriculture is an example of a coupled human-environment system that is approached in this thesis with the help of mathematical models from two directions. Firstly, the ecological subsystem is considered to find processes relevant for the effect of habitat connectivity on population abundances. Modelling theory predicts that the species-specific growth parameters (intrinsic growth rate and carrying capacity) indicate whether dispersal has a positive or negative effect on the total population size at equilibrium (r-K relationship). We use laboratory experiments in combination with a system of ordinary differential equations and deliver the first empirical evidence for a negative effect of dispersal on the population size in line with this theory. The result is of particular relevance for the design of dispersal corridors or stepping stones which are meant to increase connectivity between habitats. These measures might not be effective for biological conservation. A second population model, consisting of two coupled Ricker maps with a mate-finding Allee effect, is analyzed in order to examine the effect of bistability due to the Allee effect in combination with overcompensation in a spatial system. The interplay can cause complex population dynamics including multiple coexisting attractors, long transients and sudden population collapses. Essential extinction teaches us that not only small populations are prone to extinction but chaotic dynamics can drive a population extinct in a short period of time as well. By a comprehensive model analysis, we find that dispersal can prevent essential extinction of a population. In the context of conservation that is: habitat connectivity can promote rescue effects to save a population that exhibits an Allee effect. The two findings of the first part of this thesis have contrasting implications for conservation which shows that universal recommendations regarding habitat connectivity are impossible without knowledge of the specific system. Secondly, a model for the socio-economic subsystem is presented. Agri-environment schemes (AES) are payments that compensate farmers for forgone profits on the condition that they improve the ecological state of the agricultural system. However, classical economic models that describe the cost-effectiveness of AES often do not take the social network of farmers into account. Numerical simulations of the socio-economic model presented in this thesis suggest that social norms can hinder farmers from scheme participation. Moreover, social norms lead to multistability in farmers’ land-use decision behaviour. Informational campaigns potentially decrease the threshold towards more long-term scheme participation and might be a good tool to complement compensation payments if social norms affect land-use decisions. Finally, a coupled human-environment system is analyzed. An integrated economicecological model is studied to investigate the cost-effectiveness of AES if the species of concern exhibits an Allee effect. A numerical model analysis indicates large trade-offs between agricultural production and persistence probability. Moreover, conservation success strongly depends on the initial population size, meaning that conservation is well advised to start before the species is threatened. Spatial aggregation of habitat can promote rescue effects, suggesting land-sparing solutions for conservation. In that case,agglomeration bonuses may serve to increase the effectiveness of AES. Possible causes for population declines are diverse and can be a combination of human influences, e.g. due to habitat degradation and inherent ecosystem properties. That complicates the task of conservation. The models presented in this thesis simplify complex systems in order to extract processes relevant for biological conservation. The analysis of spatial effects and dynamical model complexity, e.g. due to Allee effects or a nonlinear utility function, allows us improve the understanding of coupled human-environment systems.

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49

Jaw, Woan-Ling, and 趙婉玲. "The Relationship between Urban Development and Water Resouces of Taipei Region : Applied Ecological-Economic System Model and Dynamic Simulation." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/63522196186413270628.

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碩士
國立中興大學
都市計劃研究所
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Due to the rapid economic growth during the past decades, our cities grow and prosper speedily. However, the "demand- oriented" planning effort has deepen the unbalance of between demand and supply of water resources and the cost of hazard. From the literatures, water resources planners build water infrastructures forethoughtly also induce the development, which is not just the one-way effect of urban development on water constructions. Therefore, on the basis of macro, holistic, policy analysis, and "symbiosis between human and water" viewpoint, this research incorporates the method of ecological-economic system model and dynamic simulation to discuss the interaction between urban development, natural environment, and water resource system in Taipei Region. With the development of the system model comprising three sub-systems, this research observes the change and the inter-dependence between system components. The result of this simulation can not only portray the inter- relationship between natural environment, water resource system and urban area in Taipei Region, but also can discuss the influences of systems using "what if" analysis about the policies change: prices, watershed conservation, water saving, system loss lessening, and growth management. In addition, the results of scenario analysis of the future development alternatives indicate that the environmental conservation based economic development can balance the objectives of environmental conservation and efficient water utilization , that is, to use the resources and develop the city sustainably.

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Spivey, Benjamin James. "Dynamic modeling, model-based control, and optimization of solid oxide fuel cells." Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-08-4325.

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Solid oxide fuel cells are a promising option for distributed stationary power generation that offers efficiencies ranging from 50% in stand-alone applications to greater than 80% in cogeneration. To advance SOFC technology for widespread market penetration, the SOFC should demonstrate improved cell lifetime and load-following capability. This work seeks to improve lifetime through dynamic analysis of critical lifetime variables and advanced control algorithms that permit load-following while remaining in a safe operating zone based on stress analysis. Control algorithms typically have addressed SOFC lifetime operability objectives using unconstrained, single-input-single-output control algorithms that minimize thermal transients. Existing SOFC controls research has not considered maximum radial thermal gradients or limits on absolute temperatures in the SOFC. In particular, as stress analysis demonstrates, the minimum cell temperature is the primary thermal stress driver in tubular SOFCs. This dissertation presents a dynamic, quasi-two-dimensional model for a high-temperature tubular SOFC combined with ejector and prereformer models. The model captures dynamics of critical thermal stress drivers and is used as the physical plant for closed-loop control simulations. A constrained, MIMO model predictive control algorithm is developed and applied to control the SOFC. Closed-loop control simulation results demonstrate effective load-following, constraint satisfaction for critical lifetime variables, and disturbance rejection. Nonlinear programming is applied to find the optimal SOFC size and steady-state operating conditions to minimize total system costs.
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