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Contribuição da inércia térmica na eficiência energética de edifícios de escritórios na cidade de São Paulo. / Effect of the thermal inertia on the energy performance of office buildings in the city of São Paulo.Brito, Adriana Camargo de 02 October 2015 (has links)
Diante das crises energéticas mundiais é oportuna a retomada de técnicas passivas de climatização de ambientes, como aquelas que consideram a inércia térmica das edificações. No Brasil é reconhecida a sua importância na melhoria do desempenho térmico de habitações, como indicado na norma NBR 15575 que, no método simplificado de avaliação do desempenho térmico, estabelece valores limites para a transmitância térmica e para a capacidade térmica de paredes, de modo a contemplar a influência da inércia térmica. Entretanto, não se dispõe de informações que permitam extrapolar esses critérios para edifícios de escritórios, que têm diferentes dinâmicas de uso e volumetria. Tendo como principal objetivo apresentar recomendações e critérios para o projeto de edifícios de escritórios na cidade de São Paulo, onde a inércia térmica dos ambientes pode contribuir para a redução ou a eliminação do uso de sistemas de ar condicionado, foi desenvolvido o presente trabalho. Para tal foram efetuadas simulações computacionais da resposta térmica de escritórios, analisados com variações nos seguintes parâmetros: área de piso; proporção de área na fachada em relação ao seu volume; nível de ocupação; taxa de ventilação; cor da fachada; sombreamento de aberturas; tipo de parede e temperatura de referência para o conforto térmico dos usuários. De modo geral, os resultados demonstraram que: ambientes ocupados, com paredes de maior capacidade térmica, menor área de piso e maior área na fachada em relação ao volume do ambiente, têm melhor desempenho térmico, especialmente com o uso de cores claras nas fachadas e dispositivos de sombreamento em aberturas. Tais características têm contribuição mais significativa na redução da demanda por climatização de ambientes somente se for adotada uma temperatura de referência do ar interior acima dos valores tipicamente usados nessas edificações. As recomendações e critérios apresentados para o projeto de escritórios consideram o uso de ambientes com ventilação, utilizando-se sistemas de climatização somente em menos de 15% das horas de um ano típico da cidade de São Paulo. / The global energy crises provide a further reason to use passive techniques, such as the thermal inertia, for cooling buildings. In Brazil, the importance of thermal inertia for the improvement of the thermal performance of dwellings is recognized and has been incorporated into the standard NBR 15575. For the assessment of the thermal performance, this standard establishes limit values for the thermal transmittance and the thermal capacity of walls, taking into account the influence of thermal inertia. However, there is no equivalent information available for offices, which can have very different characteristics. This thesis develops recommendations and criteria for the design of office buildings in the city of São Paulo, where the thermal inertia contributes to a reduction of energy consumption for cooling. Parametric simulations of typical offices were performed, varying the following parameters: floor area; façade-surface-area/volume ratio; internal gains (people, equipment etc.); ventilation rate; facade color and shading. The results showed that offices with walls made of components with higher thermal capacity, smaller floor area and larger façade-surface-area/volume ratio have better thermal performance. Light colors of the façade, shading devices and increased ventilation rate provided further improvement in the thermal performance of the offices. These characteristics may have significant contribution in reducing the energy demand for cooling depending on the value of the inside air temperature adopted. The recommendations and criteria presented for design of offices consider the use of air conditioning in less than 15% of the hours in a typical year in the city of São Paulo.
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Advanced Solutions for Renewable Energy Integration into the Grid Addressing Intermittencies, Harmonics and Inertial ResponseAnzalchi, Arash 09 November 2017 (has links)
Numerous countries are trying to reach almost 100\% renewable penetration. Variable renewable energy (VRE), for instance wind and PV, will be the main provider of the future grid. The efforts to decrease the greenhouse gasses are promising on the current remarkable growth of grid connected photovoltaic (PV) capacity. This thesis provides an overview of the presented techniques, standards and grid interface of the PV systems in distribution and transmission level. This thesis reviews the most-adopted grid codes which required by system operators on large-scale grid connected Photovoltaic systems. The adopted topologies of the converters, the control methodologies for active - reactive power, maximum power point tracking (MPPT), as well as their arrangement in solar farms are studied.
The unique L(LCL)2 filter is designed, developed and introduced in this thesis. This study will help researchers and industry users to establish their research based on connection requirements and compare between different existing technologies. Another, major aspect of the work is the development of Virtual Inertia Emulator (VIE) in the combination of hybrid energy storage system addressing major challenges with VRE implementations.
Operation of a photovoltaic (PV) generating system under intermittent solar radiation is a challenging task. Furthermore, with high-penetration levels of photovoltaic energy sources being integrated into the current electric power grid, the performance of the conventional synchronous generators is being changed and grid inertial response is deteriorating. From an engineering standpoint, additional technical measures by the grid operators will be done to confirm the increasingly strict supply criteria in the new inverter dominated grid conditions.
This dissertation proposes a combined virtual inertia emulator (VIE) and a hybrid battery-supercapacitor-based energy storage system . VIE provides a method which is based on power devices (like inverters), which makes a compatible weak grid for integration of renewable generators of electricity. This method makes the power inverters behave more similar to synchronous machines. Consequently, the synchronous machine properties, which have described the attributes of the grid up to now, will remain active, although after integration of renewable energies. Examples of some of these properties are grid and generator interactions in the function of a remote power dispatch, transients reactions, and the electrical outcomes of a rotating bulk mass.
The hybrid energy storage system (HESS) is implemented to smooth the short-term power fluctuations and main reserve that allows renewable electricity generators such as PV to be considered very closely like regular rotating power generators. The objective of utilizing the HESS is to add/subtract power to/from the PV output in order to smooth out the high frequency fluctuations of the PV power, which may occur due to shadows of passing cloud on the PV panels. A control system designed and challenged by providing a solution to reduce short-term PV output variability, stabilizing the DC link voltage and avoiding short term shocks to the battery in terms of capacity and ramp rate capability.
Not only could the suggested system overcome the slow response of battery system (including dynamics of battery, controller, and converter operation) by redirecting the power surges to the supercapacitor system, but also enhance the inertial response by emulating the kinetic inertia of synchronous generator.
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Why Medicare Part D beneficiaries do not switch plans: testing a model of Part D plan information processingHan, Jayoung 01 December 2014 (has links)
Previous studies have shown that Medicare Part D beneficiaries tend not to switch plans even though they are encouraged to reevaluate their current plans and switch plans if needed every year. Little is known about why this "plan stickiness" occurs, so there is a critical need to better understand this non-switching behavior.
This dissertation project aimed to describe how Part D beneficiaries processed information and how they perceived the plan switching process. It also aimed to describe how switchers and non-switchers were different and to test a model of Part D plan information processing that adapted from Motivation, Opportunity, and Ability (MOA) model.
To achieve these objectives, this study had a cross-sectional descriptive design and used a mixed- methods approach consisting of focus groups, interviews, and mailed survey. The qualitative study sample was recruited from two cities in Iowa and transcripts of audio-recorded discussions were analyzed. The population studied in the quantitative phase was voter registered Iowa Part D beneficiaries who were older than 65 and did not receive Low Income Subsidies (LIS). Stratified random sampling was used to identify survey subjects. An eight page survey assessing factors related to Part D plan decisions was developed and mailed to 2,250 subjects, with reminder postcards as well as phone calls used to increase response rate. Finally, confirmatory factor analysis and structural equation modeling (SEM) were used to test a model of Part D plan information processing.
A total of 16 participants from three focus groups and three interviews were included in the qualitative analysis. The results indicated that Part D beneficiaries processed different amounts of information even though they made the same decision (i.e. non-switching); whether to receive help from others in reviewing coverage options emerged as an important theme in the plan switching decision.
A usable response rate of 22.5 percent was obtained. Of this sample, 264 respondents were non-LIS Part D beneficiaries and were used for further analysis. About one fifth of the sample switched plan between 2012 and 2013, supporting existing literature that has reported a low plan switching rate. Switchers and non-switchers had few demographic differences, but twice as many switchers as non-switchers received help from others in reviewing coverage options. The results from the SEM analysis indicated that those who had lower risk perception about plan switching, higher motivation, and higher self-efficacy were likely to read larger amounts of plan information. They also indicted that higher perceived risk, involvement, and self-efficacy were positively associated with motivation to process plan information.
The findings of this dissertation suggest that plan stickiness has two types - active (i.e. informed choice) and passive (i.e. inertia) - depending on the amount of information processed, which was determined by beneficiaries' levels of perceived risk, motivation, self-efficacy, and needs. Furthermore, findings suggest that whether to receive help in understanding plan information may play a large role in leading informed beneficiaries to act on their knowledge and switch plans.
The present study is the first to integrate the concept of information processing to understand Part D beneficiaries' plan switching decisions and the first to examine psychological factors affecting beneficiaries' information processing as well as their plan switching decisions. Study findings will help policy makers developing efficient communication strategies with beneficiaries to help them to make informed choices.
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The influence of Hall currents, plasma viscosity and electron inertia on magnetic reconnection solutionsSenanayake, Tissa January 2007 (has links)
Abstract This thesis examines magnetic reconnection in the solar corona. Magnetic reconnection is the only mechanism which allows the magnetic topology of magnetized plasmas to be changed. Many of the dynamic processes in the Sun's atmosphere are believed to be driven by magnetic reconnection and studying the behaviour of such phenomena is a key step to understanding the reconnection mechanism. In Chapters 1 to 3, we discuss the physical and mathematical framework on which current magnetohydrodynamic reconnection models are based. The aim of the thesis is to investigate theoretical models of magnetic reconnection using variety of analytic and numerical techniques within the theoretical frame work of magnetohydrodynamics (MHD). In Chapter 4 we use a line-tied X-point collapse model for compressible plasmas to investigate the role of viscosity on the energy release mechanism. This model also provides the basis for the investigation of Chapter 5 which explores the impact of Hall currents in the transient X-point energy dissipation. Chapter 6 is concerned with how reconnection is modified in the presence of generalized Ohm's law which includes both Hall current and electron inertia contributions. In contrast to the closed X-point collapse geometry adopted for compressible plasmas previously, we find it more convenient to explore this problem using an open incompressible geometry in which plasma is continually entering and exiting the reconnection region. Specially, we find the scaling of the Hall-MHD system size analytically, rather than numerically as in the X-point problem of Chapter 5. Chapter 7 summarizes the results of investigations in Chapters 4, 5 and 6.
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Remote Sensing of Sediments and Volatiles on the Martian Surface and Terrestrial Analog SitesHardgrove, Craig James 01 May 2011 (has links)
The role of water and volatiles in the solar system is of critical interest in planetary science. Evidence for the past action of water or direct observation of water on a planetary body can indicate the potential to harbor life and is critical to human exploration of the solar system. We study two very different remote sensing techniques that address the issue of identifying water-related processes on the surface of other planetary bodies, and in particular, Mars. The first technique, combined thermal infrared and visible imaging, has been used extensively on Mars for determining the thermal inertia of surface materials. In the second part of this dissertation, we develop a technique that combines remote thermophysical and visible data sets with ground-based field investigations for the identification of sedimentary features at the surfaces of alluvial fans. Several methods for remotely identifying sedimentary features will be explored using thermal and visible images. We combine results from pre-existing ground-based studies with thermal images and ground-based field investigations to develop a robust technique to be used on a variety of alluvial fans. In the third part, we characterize the remote thermophysical and visible properties of specific classes of sedimentary features on alluvial fans using the technique developed in part two. The second remote sensing technique, neutron spectroscopy, has been used on many planetary spacecraft missions for the identification of hydrogen on planetary surfaces. The Dynamic Albedo of Neutrons (DAN) instrument on the upcoming Mars Science Laboratory rover mission represents a new type of neutron detector for planetary spacecraft, with the neutron detectors mounted to a rover on the Martian surface (as opposed to in orbit around the planetary body) and neutron counts that are binned by time, energy, and location (as opposed to just by energy and location). In chapter four, we model expected neutron energies and arrival times for geologic settings where water has altered the chemistry of the near surface using available geochemical data from the Mars Exploration Rovers (MER). Particle transport models are used to determine the sensitivity of neutron detection techniques to the variations in hydrogen abundance, hydrogen layering and chemical composition measured by MER.
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Understanding Institutional Change and Resistance to Change Towards Sustainability: An Interdisciplinary Theoretical Framework and Illustrative Application to Provincial-Municipal Aggregates PolicyMarkvart, Tanya, Irene January 2009 (has links)
This study develops an interdisciplinary theoretical framework for understanding institutional change and resistance to change towards sustainability. The research rests on two leading theories of change within the social and ecological sciences: the New Institutionalism and Panarchy theory. A theoretical framework integrating insights from the two theories is applied in an analysis of the development of the Town of Caledon’s mineral resources policies. The research suggests that institutional change and inertia are interconnected and interdependent and, depending on the case and context, they may interact with each other across spatial and temporal scales. There may be overlap in the emergence of pressures for institutional inertia and change across temporal and spatial scales, and both institutional change and inertia may be present when opportunities arise for renegotiation of the “rules of the game”. Results show that the two theories share many concepts (e.g., thresholds or tipping points, fast and slow moving variables, etc.) to aid in understanding the dynamics of institutional and ecological realms. Moreover, the integrated theoretical framework can help to explain the dynamics of institutional systems in a way that overcomes the limitations in Panarchy and the New Institutionalism theories by themselves. Key concepts within Panarchy theory (e.g., regime shifts, etc.) complement the New Institutionalism’s ability to capture important contextual factors influencing institutional change and inertia, and help to overcome the current limitation in its capacity to explain the nonlinear, multi-scalar dynamics of institutional systems. In turn, key concepts within the New Institutionalism (e.g., uncertainty, etc.) complement and enrich Panarchy theory’s capacity to illustrate the social and economic dimensions of institutional dynamics. Results of the case analysis demonstrate that a range of overlapping, historic and immediate, local-to-provincial factors (e.g., socioeconomic costs, uncertainty, path dependent effects, etc.) and institutional elements (e.g., interests and values, power and resources, issues of fit, etc.) drove institutional change and inertia in the development of Caledon’s mineral resources policies. The slow moving institutional variables in Caledon’s case (core Town, industry and provincial government values and interests) were perhaps the greatest determinants of institutional change and resistance to change towards sustainability. The story of the development of Caledon’s mineral resources policies, then, is about the resilience and resistance efforts of a small Town committed to maintaining core community values under the constraints of a resilient and resistant, ecologically destructive and inequitable institutional system.
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Incumbent firms and Response to Disruptive Innovation through Value Network Management : Lessons from Eastman Kodak‟s failure in the digital eraGebremeskel Tesfaye, Helen, Nguyen, Thi Hong Nhung January 2012 (has links)
AbstractTitle: Incumbent firms and Response to Disruptive Innovation through Value Network Management - Lessons from Eastman Kodak‟s failure in the digital eraAuthors: Helen Gebremeskel Tesfaye & Thi Hong Nhung NguyenSupervisor: Marie BengtssonBackgroundThe question of why incumbent or established firms get into difficulties when they are faced with disruptive innovations has been extensively researched and discussed by many authors. Many explanations given for such failure seem to take “inside-out” approach by focusing on problems of organizational inertia, complacency, lack of insight and incompetence. On the other hand, Christensen‟s (1997; 2003) explanation takes an “outside-in” approach by focusing on the role of established firms‟ value network, particularly mainstream customers, as a determining factor to what incumbent firms can and cannot do.Purpose(i) Examine comprehensively the impacts of the value network on the incumbent firms when they are challenged by the arrival of disruptive innovations; (ii) Developing a model for the incumbent firms to recognize and manage effectively changes occurring in the value network in the face of disruptive innovations; and (iii) Gain a new insight into Kodak‟s failure in the reign of digital technology from the value network management perspective.DefinitionsDisruptive Innovation: Disruptive innovations in this study are considered as new products based on new technologies and which provide different attributes or product characteristics than what the company‟s mainstream or established customer segments historically value, while at the same time bringing new performance attributes to the market.iiValue Network: Value network is the context or environment within which a firm identifies and responds to customers‟ needs, solves problems, procures input, reacts to competitors and strives for profit.ResultsA Value Network Management model is developed for the incumbent firms to recognize and manage effectively changes occurring in the value network caused by the arrival of disruptive innovations. More specifically, the model aims at helping firms to overcome insight and action inertia and to choose the right partners among various new actors entering the value network. This model is iterative in essence and incorporates steps of searching/scanning, value network analysis and partner selection on the basis of appropriate role selection in the value network.
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Understanding Institutional Change and Resistance to Change Towards Sustainability: An Interdisciplinary Theoretical Framework and Illustrative Application to Provincial-Municipal Aggregates PolicyMarkvart, Tanya, Irene January 2009 (has links)
This study develops an interdisciplinary theoretical framework for understanding institutional change and resistance to change towards sustainability. The research rests on two leading theories of change within the social and ecological sciences: the New Institutionalism and Panarchy theory. A theoretical framework integrating insights from the two theories is applied in an analysis of the development of the Town of Caledon’s mineral resources policies. The research suggests that institutional change and inertia are interconnected and interdependent and, depending on the case and context, they may interact with each other across spatial and temporal scales. There may be overlap in the emergence of pressures for institutional inertia and change across temporal and spatial scales, and both institutional change and inertia may be present when opportunities arise for renegotiation of the “rules of the game”. Results show that the two theories share many concepts (e.g., thresholds or tipping points, fast and slow moving variables, etc.) to aid in understanding the dynamics of institutional and ecological realms. Moreover, the integrated theoretical framework can help to explain the dynamics of institutional systems in a way that overcomes the limitations in Panarchy and the New Institutionalism theories by themselves. Key concepts within Panarchy theory (e.g., regime shifts, etc.) complement the New Institutionalism’s ability to capture important contextual factors influencing institutional change and inertia, and help to overcome the current limitation in its capacity to explain the nonlinear, multi-scalar dynamics of institutional systems. In turn, key concepts within the New Institutionalism (e.g., uncertainty, etc.) complement and enrich Panarchy theory’s capacity to illustrate the social and economic dimensions of institutional dynamics. Results of the case analysis demonstrate that a range of overlapping, historic and immediate, local-to-provincial factors (e.g., socioeconomic costs, uncertainty, path dependent effects, etc.) and institutional elements (e.g., interests and values, power and resources, issues of fit, etc.) drove institutional change and inertia in the development of Caledon’s mineral resources policies. The slow moving institutional variables in Caledon’s case (core Town, industry and provincial government values and interests) were perhaps the greatest determinants of institutional change and resistance to change towards sustainability. The story of the development of Caledon’s mineral resources policies, then, is about the resilience and resistance efforts of a small Town committed to maintaining core community values under the constraints of a resilient and resistant, ecologically destructive and inequitable institutional system.
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Policy interia hypothesis or unobserved variable hypothesis in Taiwan¡¦s Interest-rate rule?Shiu, Kai-hung 29 June 2011 (has links)
This paper adopts an modle with endogenous variable to investigates policy inertia hypothesis or unobserved variable hypothesis in Taiwan¡¦s interest-rate rule 1981-
2010. Empirical result suggests that both policy inertia and omitted variable hypothesis are important in monetary policy in Taiwan,which is consistent with that of Gerlach-
Kristen (2004).
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Developing a Dual Factor Model to Investigate Technology Product Users¡¦ Continue to Use Intention-The Case of AndroidHsu, Chieh-Ju 20 August 2012 (has links)
Smart phones are an important facet of the functionality of daily life. The main smart phone operating systems are Android and iOS. We cannot predict which one will be the winning smart phone operating system in the future. Hence, it is an important issue for consumers and enterprises to know which factors influence consumers to continue to use Android. We construct a dual factor model to explain consumers¡¦ Android use continuance. The dual factors include (1) dedication vs. constraint, (2) cognitive constraints vs. psychological constraints, and (3) internal lock effect vs. external lock effect.
Data collected from 296 Android consumers in Taiwan were tested against the research model and confirmed our hypotheses. The results support the theoretical model in explaining the effect of ECT theory and status quo bias theory on consumers¡¦ intentions to continue to use Android. Finally, we find inertia is the most important factor influencing consumers¡¦ continued use of Android.
The main contribution of this study is to provide a dual factor model for consumers¡¦ use continuance behavior. This model can also be applied to different technology products.
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