<p>This dissertation studies the optimal control of two different dynamic systems with learning: (i) diagnostic service systems, and (ii) green incentive policy design. In both cases, analytical models have been developed to improve our understanding of the system, and managerial insights are gained on its optimal management.</p><p>We first consider a diagnostic service system in a queueing framework, where the service is in the form of sequential hypothesis testing. The agent should dynamically weigh the benefit of performing an additional test on the current task to improve the accuracy of her judgment against the incurred delay cost for the accumulated workload. We analyze the accuracy/congestion tradeoff in this setting and fully characterize the structure of the optimal policy. Further, we allow for admission control (dismissing tasks from the queue without processing) in the system, and derive its implications on the structure of the optimal policy and system's performance.</p><p>We then study Feed-in-Tariff (FIT) policies, which are incentive mechanisms by governments to promote renewable energy technologies. We focus on two key network externalities that govern the evolution of a new technology in the market over time: (i) technological learning, and (ii) social learning. By developing an intertemporal model that captures these dynamics, we investigate how lawmakers should leverage on such effects to make FIT policies more efficient. We contrast our findings against the current practice of FIT-implementing jurisdictions, and also determine how the FIT regimes should depend on specific technology and market characteristics.</p> / Dissertation

Global cities have recognized the need to reduce greenhouse gas (GHG) emissions and have begun to take action to balance of the carbon cycle. This thesis examines the nuances of quantification methods used and the implications of current policy for long-term emissions. Emissions from waste management, though relatively small when compared with building and transportation sectors, are the largest source of emissions directly controlled by municipal government. It is important that municipalities understand the implications of methodological selection when quantifying GHG emissions from waste management practices. The “Waste-in-Place” methodology is presented as the most relevant for inventorying purposes, while the “Methane Commitment” approach is best used for planning. Carbon sinks, divided into “Direct” and “Embodied”, are quantified using the Greater Toronto Area (GTA) as a case study. “Direct” sinks, those whose sequestration processes occur within urban boundaries, contribute the largest share of carbon sinks with regional forests providing a significant proportion. “Embodied” sinks, those whose sequestration processes (or in the case of concrete, the processes that enable sequestration) are independent of the urban boundary, can contribute to the urban carbon pool, but greater uncertainty exists in upstream emissions as the management/processing prior to its use as a sink are generally beyond the consumer’s purview. The Pathways to Urban Reductions in Greenhouse gas Emissions (or PURGE) model is developed as a means to explore emissions scenarios resulting from urban policy to mitigate climate change by quantifying future carbon sources/sinks (from changes in building stock, vehicle stock, waste treatment and urban/regional forests). The model suggests that current policy decisions in the GTA provide short-term reductions but are not sufficient in the long term to balance the pressures of economic and population growth. Aggressive reductions in energy demand from personal transportation and existing building stock will be necessary to achieve long-term emissions targets.

Global cities have recognized the need to reduce greenhouse gas (GHG) emissions and have begun to take action to balance of the carbon cycle. This thesis examines the nuances of quantification methods used and the implications of current policy for long-term emissions. Emissions from waste management, though relatively small when compared with building and transportation sectors, are the largest source of emissions directly controlled by municipal government. It is important that municipalities understand the implications of methodological selection when quantifying GHG emissions from waste management practices. The “Waste-in-Place” methodology is presented as the most relevant for inventorying purposes, while the “Methane Commitment” approach is best used for planning. Carbon sinks, divided into “Direct” and “Embodied”, are quantified using the Greater Toronto Area (GTA) as a case study. “Direct” sinks, those whose sequestration processes occur within urban boundaries, contribute the largest share of carbon sinks with regional forests providing a significant proportion. “Embodied” sinks, those whose sequestration processes (or in the case of concrete, the processes that enable sequestration) are independent of the urban boundary, can contribute to the urban carbon pool, but greater uncertainty exists in upstream emissions as the management/processing prior to its use as a sink are generally beyond the consumer’s purview. The Pathways to Urban Reductions in Greenhouse gas Emissions (or PURGE) model is developed as a means to explore emissions scenarios resulting from urban policy to mitigate climate change by quantifying future carbon sources/sinks (from changes in building stock, vehicle stock, waste treatment and urban/regional forests). The model suggests that current policy decisions in the GTA provide short-term reductions but are not sufficient in the long term to balance the pressures of economic and population growth. Aggressive reductions in energy demand from personal transportation and existing building stock will be necessary to achieve long-term emissions targets.

No description available.

No description available.

This thesis is an analysis of technology diffusion and the long-run institutional impact of the nature of that diffusion. It examines how a growing commercial trading relationship with Lancashire-based millwrights enabled textile industrialisation in late 19th century Bombay, and reflects upon the evolving character of Indian manufacturing and organisational behaviour within and beyond the colonial context, and into 21st century industrial strategy. Drawing upon primary archival material from sources in Britain and India (including historical company records, trade association records, transactional correspondence between Lancashire and Bombay, and administrative records of the India Office in Whitehall), and upon 27 elite interviews with prominent Mumbai-based businessmen and their families, a technological and cultural dependence by manufacturing elites upon the commercial agent is identified. The emplacement of colonial business norms and particularly the use of informal networks, in turn bolstered by a culture for clubbability, appears to influence the distinctly tight-knit, ‘gentlemanly’ character of Indian family business houses established during the late 19th and early 20th century. Applying a mixed-methods approach to technology theory and analysis, the data chapters are split into two parts, respectively concerning info rmation flows and knowledge flows from the UK to Western India. The former explores patterns in technological transactions and decisions governing the diffusion of textile technology that enabled industrial establishment. The latter focuses on the replication of managerial, cultural and business practices following and reflecting upon Bombay’s textile industrialisation; this establishes the observed presence of British ideals of gentlemanly business conduct within informal networks, familial and community ties. Overall, this research highlights how business history may be used as a lens to understand the process of technology diffusion and analyse the reinforcement of culturally-hybrid social norms in peripheral regions via technical or commercial links. In terms of developmental trajectory, moreover, this case study considers how given limited capacity for innovation or capital goods production, strategic supply-side decisions may garner early cumulative value by replicating industrial production, albeit with long-term institutional consequences. This research has implications for future understanding of the development of UK-Commonwealth trading relationships, and how these might foster structural transformation in the so-called Fourth Industrial Revolution. While this thesis focuses on the diffusion of physical capital and technology-driven industry, such a narrative exploration of networks and business norms surrounding structural transformation might be pursued based on alternative factors of production including capital investment and flow, or else feasibly extend into other post-colonial regions.

The Steiner Tree problem has appeared in the Karp's list of the first 21 NP-hard problems and is well known as one of the most fundamental problems in Network Design area. We study the Node-Weighted version of the Prize Collecting Steiner Tree problem. In this problem, we are given a simple graph with a cost and penalty value associated with each node. Our goal is to find a subtree T of the graph minimizing the cost of the nodes in T plus penalty of the nodes not in T. By a reduction from set cover problem it can be easily shown that the problem cannot be approximated in polynomial time within factor of (1-o(1))ln n unless NP has quasi-polynomial time algorithms, where n is the number of vertices of the graph. Moss and Rabani claimed an O(log n)-approximation algorithm for the problem using a Primal-Dual approach in their STOC'01 paper \cite{moss2001}. We show that their algorithm is incorrect by providing a counter example in which there is an O(n) gap between the dual solution constructed by their algorithm and the optimal solution. Further, evidence is given that their algorithm probably does not have a simple fix. We propose a new algorithm which is more involved and introduces novel ideas in primal dual approach for network design problems. Also, our algorithm is a Lagrangian Multiplier Preserving algorithm and we show how this property can be utilized to design an O(log n)-approximation algorithm for the Node-Weighted Quota Steiner Tree problem using the Lagrangian Relaxation method. We also show an application of the Node Weighted Quota Steiner Tree problem in designing algorithm with better approximation factor for Technology Diffusion problem, a problem proposed by Goldberg and Liu in \cite{goldberg2012} (SODA 2013). In Technology Diffusion, we are given a graph G and a threshold θ(v) associated with each vertex v and we are seeking a set of initial nodes called the seed set. Technology Diffusion is a dynamic process defined over time in which each vertex is either active or inactive. The vertices in the seed set are initially activated and each other vertex v gets activated whenever there are at least θ(v) active nodes connected to v through other active nodes. The Technology Diffusion problem asks to find the minimum seed set activating all nodes. Goldberg and Liu gave an O(rllog n)-approximation algorithm for the problem where r and l are the diameter of G and the number of distinct threshold values, respectively. We improve the approximation factor to O(min{r,l}log n) by establishing a close connection between the problem and the Node Weighted Quota Steiner Tree problem.

The Steiner Tree problem has appeared in the Karp's list of the first 21 NP-hard problems and is well known as one of the most fundamental problems in Network Design area. We study the Node-Weighted version of the Prize Collecting Steiner Tree problem. In this problem, we are given a simple graph with a cost and penalty value associated with each node. Our goal is to find a subtree T of the graph minimizing the cost of the nodes in T plus penalty of the nodes not in T. By a reduction from set cover problem it can be easily shown that the problem cannot be approximated in polynomial time within factor of (1-o(1))ln n unless NP has quasi-polynomial time algorithms, where n is the number of vertices of the graph. Moss and Rabani claimed an O(log n)-approximation algorithm for the problem using a Primal-Dual approach in their STOC'01 paper \cite{moss2001}. We show that their algorithm is incorrect by providing a counter example in which there is an O(n) gap between the dual solution constructed by their algorithm and the optimal solution. Further, evidence is given that their algorithm probably does not have a simple fix. We propose a new algorithm which is more involved and introduces novel ideas in primal dual approach for network design problems. Also, our algorithm is a Lagrangian Multiplier Preserving algorithm and we show how this property can be utilized to design an O(log n)-approximation algorithm for the Node-Weighted Quota Steiner Tree problem using the Lagrangian Relaxation method. We also show an application of the Node Weighted Quota Steiner Tree problem in designing algorithm with better approximation factor for Technology Diffusion problem, a problem proposed by Goldberg and Liu in \cite{goldberg2012} (SODA 2013). In Technology Diffusion, we are given a graph G and a threshold θ(v) associated with each vertex v and we are seeking a set of initial nodes called the seed set. Technology Diffusion is a dynamic process defined over time in which each vertex is either active or inactive. The vertices in the seed set are initially activated and each other vertex v gets activated whenever there are at least θ(v) active nodes connected to v through other active nodes. The Technology Diffusion problem asks to find the minimum seed set activating all nodes. Goldberg and Liu gave an O(rllog n)-approximation algorithm for the problem where r and l are the diameter of G and the number of distinct threshold values, respectively. We improve the approximation factor to O(min{r,l}log n) by establishing a close connection between the problem and the Node Weighted Quota Steiner Tree problem.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-08-03T18:16:36Z No. of bitstreams: 1 2017 - Jose Roberto Moreira Ribeiro Gon?alves.pdf: 2652122 bytes, checksum: a01db58ccd026d3e5dc25d586d1ee8ac (MD5) / Made available in DSpace on 2017-08-03T18:16:36Z (GMT). No. of bitstreams: 1 2017 - Jose Roberto Moreira Ribeiro Gon?alves.pdf: 2652122 bytes, checksum: a01db58ccd026d3e5dc25d586d1ee8ac (MD5) Previous issue date: 2017-02-17 / Precision agriculture has been an alternative to reduce costs in agriculture and environmental gain, and can also facilitate the localized and rational application of inputs, with positive economic, environmental and social results. Soil sampling techniques studies from the use of new sensors available in the market becomes fundamental importance. The objective of this work was to compare fertilizer recommendation maps based on three different soil sampling methods to evaluate the economic and environmental component. The experiment was carried out in three distinct areas in the cities of Guarapuava and Cantagalo, both in the state of Paran?, under no-tillage system, with crops rotation of soy, oat, corn, wheat and barley. The used sampling methods were: by altitude management zones, sample meshes and electrical conductivity oriented sampling (CEa). The soil samples for the method of altitude management zones were performed after the zones definition. Mesh sampling was performed at the density of one sample per ha. The guided sampling was carried out after the definition of management zones by electrical conductivity of the soil, through the use of soil approach sensor. From the results of the laboratory analysis, recommendation maps were made for limestone, phosphorus, potassium and nitrogen application to allow comparison between methods, volumes, environmental factors and costs. With the accomplishment of this study it was possible to evaluate the spatial variability of the soil attributes, comparing the fertilizer volumes recommended, estimating the global economic cost of using the technology by sensor, as well as all the used inputs, equipment and implements. From the environmental point of view, it was possible to quantitatively and spatially evaluate the behavior of the applications of each fertilizer by sampling method. Taking the Meshes Samples method as reference, it was presented as a better alternative compared to the other methods, however, the use of soil sensors have been presented as viable technologies that need further improvement in order to provide productivity, costs reduction and consequent economic and environmental gain. / A agricultura de precis?o tem sido uma alternativa para redu??o de custos na agricultura e ganho ambiental, podendo ainda facilitar a aplica??o localizada e racional dos insumos, com resultados econ?micos, ambientais e sociais positivos. O estudo das t?cnicas amostrais de solo a partir do uso de novos sensores dispon?veis no mercado torna-se de fundamental import?ncia. Objetivou-se no presente trabalho, comparar mapas de recomenda??o de fertilizantes baseados em tr?s diferentes m?todos de amostragem do solo para avalia??o do componente econ?mico e ambiental. O experimento foi realizado em tr?s ?reas distintas nos munic?pios de Guarapuava e Cantagalo, ambos no estado do Paran?, sob sistema de plantio direto, com rota??o das culturas de soja, aveia, milho, trigo e cevada. Os m?todos amostrais utilizados foram: por zonas de manejo por altitude, malhas amostrais e amostragem orientada por condutividade el?trica (CEa). As amostras de solo para o m?todo zonas de manejo por altitude foram realizadas ap?s a defini??o das zonas. A amostragem em malha foi realizada na densidade de uma amostra por ha. A amostragem orientada foi realizada ap?s a defini??o das zonas de manejo por condutividade el?trica do solo, por meio do uso de sensor de aproxima??o do solo. A partir dos resultados das an?lises laboratoriais, foram confeccionados mapas de recomenda??o para aplica??o de Calc?rio, F?sforo, Pot?ssio e Nitrog?nio de forma a permitir a compara??o entre os m?todos, volumes, fatores ambientais e custos. Com a realiza??o deste estudo foi poss?vel avaliar a variabilidade espacial dos atributos do solo, comparando os volumes dos fertilizantes recomendados, estimar o custo econ?mico global da utiliza??o da tecnologia via sensor, bem como de todos os insumos, equipamentos e implementos utilizados. Sob o ponto de vista ambiental, foi poss?vel avaliar de maneira quantitativa e espacial o comportamento das aplica??es cada fertilizante por m?todo amostral. Tomando-se o m?todo de Malhas Amostrais como refer?ncia, o mesmo se apresentou como a alternativa mais vi?vel comparado com os demais m?todos, por?m, o uso dos sensores do solo tem se apresentado como tecnologias vi?veis que carecem de maior aperfei?oamento no sentido de propiciar produtividade, redu??o de custos e consequente ganho econ?mico e ambiental.

全球行動電話用戶數於2002年達到12億，首度超過固定電話用戶數之11億；行動電話用戶數並於2008年達41億，為固定電話用戶數(13億)之3倍以上。行動電話相對於固定電話之主要優勢在於系統之建置成本低及佈建速度快；行動電話之快速普及已成為創新擴散研究之重要題材。 行動電話擴散之研究為選取一成長模型(例如Gompertz、Logistic或Bass模型)並類比該模型以求出擴散之參數(例如成長速率)，以進一步(1)了解相關驅動因子(例如技術創新、市場開放等)對擴散參數之影響，及(2)延伸擴散模型曲線以預測未來之成長。 惟成長模型之選取尚無原理原則可供遵循而具隨機性(ad hoc basis)。為找出模型選用之可能規律，以降低模型選用之隨機性並提高成長預測之準確度，本研究以十二個代表性國家(巴、中、法、德、印、日、韓、俄、星、台、英、美)至2007年之資料以比較三個最常用之成長模型之績效，即Gompertz、Logistic及Bass模型。模型績效逐年比較標準係採用rmse值，並輔以Friedman test檢測模型績效差異之顯著性，再對照模型之機制意涵，以進一步了解最適模型之選用原則。 此外，台灣行動電話普及率於2002年為108%居全球之冠，而中國自2001年起取代美國成為全球具最多行動電話用戶數之單一國家，台灣及中國屬行動電話擴散之重要個案，惟目前尚缺此二個案之實證研究。為補足此一缺口，本研究亦對台灣及中國行動電話擴散之驅動因子進行實證研究，以進一步了解擴散之關鍵驅動力。 研究發現由於目前統計軟體之進步，Gompertz、Logistic及Bass三模型均可獲致極佳之匹配度而難分軒輊，惟模型預測力(延伸曲線)則具差異性。12個模型選用樣本國家中之8個國家(巴、中、法、德、日、韓、英、美)係以Gompertz模型具較佳之預測力；依Gompertz模型機制意涵，代表行動電話擴散早期係受網路外部性(口耳相傳)影響，惟至擴散後期(例如過了擴散極大值之一半)則已不相關。此外，若因市場開放等重大變因造成行動電話之快速擴散，則Logistic模型具有較佳之績效，如台灣及俄羅斯屬之。依Logistic模型機制意涵，代表擴散係受網路外部性所影響。Bass模型應用於行動電擴散時，因該模型所算出之創新係數偏低，績效與Logistic模型相近，而Logistic模型為Bass模型之創新係數為0時之特例。 台灣及中國行動電話擴散之驅動因子研究發現(1)價格下降及(2)預付卡之推行對加速擴散具顯著性，兩者均對低階市場之採用具影響力。鑑於高階市場將先飽和，爰未來加速行動電話擴散之關鍵驅動因子應係與推動低階市場採用具密切相關性。以中國為例，未來市場開放競爭造成價格再度大幅下降，將進一步促低階市場採用，加速中國行動電話之普及。 / The number of mobile telephone subscriptions reached 1.2 billion globally in 2002, exceeding fixed-line telephony subscriptions (1.1 billion) for the first time. The number of mobile telephone subscriptions reached 4.1 billion globally in 2008, over three times the number of fixed-line telephone subscriptions (1.3 billion). The main advantages of mobile telephony over fixed-line are low cost and rapid facility deployment. The rapid diffusion of mobile telephony has become an important topic in innovation diffusion. The conventional approach to studying mobile telephony diffusion is to analogize a single growth model, such as the Gompertz, Logistic or Bass model, and calculate the model parameters, for example growth rate. The significance of certain selected driving forces, such as technology innovation or market competition, to the studied parameters, such as growth rate, is then estimated. The diffusion growth can also be forecast by extrapolating the diffusion curve. Utilizing the growth model analogy is the first step in analyzing mobile telephony diffusion. However, no principles or rules exit for selecting a growth model. To identify rules for model selection to reduce randomness and increase forecast accuracy, this work uses 12 sample countries, namely Brazil, China, France, Germany, India, Japan, Korea, Russia, Singapore, Taiwan, the UK and the USA, employing data prior to 2008 to compare the performance of three most commonly used models, namely the Gompertz, Logistic and Bass models. The root mean square error (rmse) is chosen as the criterion for measuring annual model performance. The work uses the Friedman test to examine the significance of differences in performance between models. The implications of model mechanisms are emphasized to investigate the selection rule for the most appropriate model. The penetration of mobile telephony in Taiwan was 108% in 2002, ranking first in the world. Furthermore, in 2001 the number of mobile telephony in China replaced the United States as number one in the world. Both Taiwan and China are important examples for mobile telephony diffusion. However, no empirical investigation has been performed in these two cases. To fill this gap, this work estimated the driving forces for mobile telephony diffusion in Taiwan and China to learn about the critical drivers of the mobile telephony diffusion. Empirical results indicate that due to improvements in statistical software, providing good fitness for all three models, namely the Gompertz, Logistic and Bass models, distinguishing which has the best fitness is difficult. However, the performance of the three models is distinguishable when forecasting based on extrapolating the diffusion curve. In eight of the 12 examples, namely Brazil, China, France, Germany, Japan, Korea, the UK and the USA, the Gompertz model is the most appropriate model for forecasting. The mechanism of the Gompertz model means that during the initial stage the diffusion is correlated with network externalities (namely word of mouth), however, this correlation reduces during the later stages (such as pass one half of the maximum potential). Moreover, the cases of Taiwan and Russia demonstrated that the Logistic model performs well provided some significant driver of the diffusion exists. The mechanism of the Logistic model means that the diffusion is correlated with network externalities throughout the whole diffusion. Furthermore, using Chinese data, when the Bass model is applied, because of its low innovation coefficient, it performs similarly to the Logistic model, which is a special case of the Bass model in which the innovation coefficient equals zero. Empirical results for the critical driving forces of mobile telephony diffusion in Taiwan and China indicate that (1) reducing prices and (2) the launch of pre-paid services are crucial to mobile telephony diffusion. Both factors are essential to mobile telephony adoption in low-end markets. The high-end market is the first to be saturated by mobile telephony adoption, future drivers of the mobile telephony diffusion should be highly correlated with low-end market demand. Taking China as an example, the opening of the market to further reduce tariffs will attract mobile telephony adoption in the low-end market, facilitating the mobile telephony diffusion.