Impacto da redução do nível de tensão na iluminação residencial em uma rede inteligente

In this paper, we will present an overview of the smart grid defining the three main systems that compose it: smart infrastructure system, smart management system and smart protection system. We will conceptualize a functionality of smart management system, the conservative voltage reduction, citing its benefits and its history of application. And, finally, we'll cover a test in which we reduce the nominal voltages on incandescent bulbs, CFL and LED, in the context of residential lighting, and on LED and HPS, in the context of public lighting. The test aims to check whether the voltage reduction adversely affects sources of lighting by measuring the temperature manually with a thermal imaging camera FLIR and illuminance with a LUX meter. The set of power factor, total harmonic distortion, and input power values will be collected automatically through the power quality Analyzer Fluke 345 with a probe Fluke Hall Effect Current. For residential lighting, it was found that both CFL and LED had good performance with the smallest variations in illuminance. Between both, the LED source had the lowest harmonics and the lowest power consumption, on the other hand incandescent bulbs had a bad performance as expected. Public light sources also had a good performance and obtained power factors within the standards, as opposed to the CFL and LED residential sources. The data collected clearly shows the feasibility for nominal voltage reductions. Even with small reductions, there are possibilities of savings which can be passed on to the utilities and consumers

Estudio de algunas problemáticas políticas a partir de parámetros de análisis de la geografía actual

El presente artículo intenta abordar el estudio de algunos de los principales problemas que nos presenta, a diversas escalas, la política actual, ateniéndonos a sus implicancias espaciales y a partir de diversos parámetros ofrecidos en los últimos tiempos por la ciencia geográfica. La propuesta se apoya en bases teóricas desarrolladas a partir de los enunciados de Emmanuel Wallerstein y Peter Taylor acerca de un sistema mundial estructurado como una economía-mundo, basada en el modo de producción capitalista. Por otra parte, intenta formular una explicación teórica acerca de la dinámica experimentada por los territorios sobre la base de la mecánica de dicho sistema mundial. A partir de estos postulados, se propone el análisis de algunos de los principales fenómenos emanados del estudio anterior y sus implicancias espaciales, como las actuales relaciones de poder en el sistema, la subsistencia de factores de poder tradicionales (el Estado-nación, las configuraciones culturales de base étnica) y la aparición de nuevos (la constitución de bloques y asociaciones supranacionales, los nuevos movimientos sociales, las nuevas formas de participación local), la importancia de los discursos hegemónicos y contrahegemónicos en la construcción de las representaciones simbólicas y de los medios de información en dichos procesos o el nuevo cuadro de las identidades e hibridaciones culturales a partir de la movilidad de la población.

Estudio de algunas problemáticas políticas a partir de parámetros de análisis de la geografía actual

El presente artículo intenta abordar el estudio de algunos de los principales problemas que nos presenta, a diversas escalas, la política actual, ateniéndonos a sus implicancias espaciales y a partir de diversos parámetros ofrecidos en los últimos tiempos por la ciencia geográfica. La propuesta se apoya en bases teóricas desarrolladas a partir de los enunciados de Emmanuel Wallerstein y Peter Taylor acerca de un sistema mundial estructurado como una economía-mundo, basada en el modo de producción capitalista. Por otra parte, intenta formular una explicación teórica acerca de la dinámica experimentada por los territorios sobre la base de la mecánica de dicho sistema mundial. A partir de estos postulados, se propone el análisis de algunos de los principales fenómenos emanados del estudio anterior y sus implicancias espaciales, como las actuales relaciones de poder en el sistema, la subsistencia de factores de poder tradicionales (el Estado-nación, las configuraciones culturales de base étnica) y la aparición de nuevos (la constitución de bloques y asociaciones supranacionales, los nuevos movimientos sociales, las nuevas formas de participación local), la importancia de los discursos hegemónicos y contrahegemónicos en la construcción de las representaciones simbólicas y de los medios de información en dichos procesos o el nuevo cuadro de las identidades e hibridaciones culturales a partir de la movilidad de la población.

Estudio de algunas problemáticas políticas a partir de parámetros de análisis de la geografía actual

El presente artículo intenta abordar el estudio de algunos de los principales problemas que nos presenta, a diversas escalas, la política actual, ateniéndonos a sus implicancias espaciales y a partir de diversos parámetros ofrecidos en los últimos tiempos por la ciencia geográfica. La propuesta se apoya en bases teóricas desarrolladas a partir de los enunciados de Emmanuel Wallerstein y Peter Taylor acerca de un sistema mundial estructurado como una economía-mundo, basada en el modo de producción capitalista. Por otra parte, intenta formular una explicación teórica acerca de la dinámica experimentada por los territorios sobre la base de la mecánica de dicho sistema mundial. A partir de estos postulados, se propone el análisis de algunos de los principales fenómenos emanados del estudio anterior y sus implicancias espaciales, como las actuales relaciones de poder en el sistema, la subsistencia de factores de poder tradicionales (el Estado-nación, las configuraciones culturales de base étnica) y la aparición de nuevos (la constitución de bloques y asociaciones supranacionales, los nuevos movimientos sociales, las nuevas formas de participación local), la importancia de los discursos hegemónicos y contrahegemónicos en la construcción de las representaciones simbólicas y de los medios de información en dichos procesos o el nuevo cuadro de las identidades e hibridaciones culturales a partir de la movilidad de la población.

Огляд наукових досліджень в галузі вивчення напружено-деформованого стану трубобетонних конструкцій

The paper presents an analytical review of the literature, which reflects the results of national and foreign scientific researches aimed to studying the features of the composition and dosage of components of self compacting concrete as one of the most promising aggregate for modern composite structures. In addition, the results of numerical and experimental researches of stress-strain state of composite structures (concrete-filled tubes) under the influence of various power factors, have been considered. The description and features of existing analytical methods for the determination of the bearing capacity of the considered structures under compression and bendings, have been given. The analysis of deformation model of confined concrete in a composition of the composite structure, as well as non-linear models of steel works with their distinctive features, has been carried out. The main approaches to the finite element modeling of composite structures have been determined.

Power Stored and Quality Factors in Frequency Selective Surfaces at THz Frequencies

A study of the external, loaded and unloaded quality factors for frequency selective surfaces (FSSs) is presented. The study is focused on THz frequencies between 5 and 30 THz, where ohmic losses arising from the conductors become important. The influence of material properties, such as metal thickness, conductivity dispersion and surface roughness, is investigated. An equivalent circuit that models the FSS in the presence of ohmic losses is introduced and validated by means of full-wave results. Using both full-wave methods as well as a circuit model, the reactive energy stored in the vicinity of the FSS at resonance upon plane-wave incidence is presented. By studying a doubly periodic array of aluminium strips, it is revealed that the reactive power stored at resonance increases rapidly with increasing periodicity. Moreover, it is demonstrated that arrays with larger periodicity-and therefore less metallisation per unit area-exhibit stronger thermal absorption. Despite this absorption, arrays with higher periodicities produce higher unloaded quality factors. Finally, experimental results of a fabricated prototype operating at 14 THz are presented.

Electricity load and price forecasting with influential factors in a deregulated power industry

With the emergence of smart power grid and distributed generation technologies in recent years, there is need to introduce new advanced models for forecasting. Electricity load and price forecasts are two primary factors needed in a deregulated power industry. The performances of the demand response programs are likely to be deteriorated in the absence of accurate load and price forecasting. Electricity generation companies, system operators, and consumers are highly reliant on the accuracy of the forecasting models. However, historical prices from the financial market, weekly price/load information, historical loads and day type are some of the explanatory factors that affect the accuracy of the forecasting. In this paper, a neural network (NN) model that considers different influential factors as feedback to the model is presented. This model is implemented with historical data from the ISO New England. It is observed during experiments that price forecasting is more complicated and hence less accurate than the load forecasting.

Power, privilege and HIV prevalence: examination of sexual HIV-risk factors in MSM and transgender women who engage in transactional sex

Thesis (Master's)--University of Washington, 2016-06

Investigation of factors driving the costs of operating the 2020 Irish power system with large-scale wind generation

The main goal of this work is to determine the true cost incurred by the Republic of Ireland and Northern Ireland in order to meet their EU renewable electricity targets. The primary all-island of Ireland policy goal is that 40% of electricity will come from renewable sources in 2020. From this it is expected that wind generation on the Irish electricity system will be in the region of 32-37% of total generation. This leads to issues resulting from wind energy being a non-synchronous, unpredictable and variable source of energy use on a scale never seen before for a single synchronous system. If changes are not made to traditional operational practices, the efficient running of the electricity system will be directly affected by these issues in the coming years. Using models of the electricity system for the all-island grid of Ireland, the effects of high wind energy penetration expected to be present in 2020 are examined. These models were developed using a unit commitment, economic dispatch tool called PLEXOS which allows for a detailed representation of the electricity system to be achieved down to individual generator level. These models replicate the true running of the electricity system through use of day-ahead scheduling and semi-relaxed use of these schedules that reflects the Transmission System Operator's of real time decision making on dispatch. In addition, it carefully considers other non-wind priority dispatch generation technologies that have an effect on the overall system. In the models developed, three main issues associated with wind energy integration were selected to be examined in detail to determine the sensitivity of assumptions presented in other studies. These three issues include wind energy's non-synchronous nature, its variability and spatial correlation, and its unpredictability. This leads to an examination of the effects in three areas: the need for system operation constraints required for system security; different onshore to offshore ratios of installed wind energy; and the degrees of accuracy in wind energy forecasting. Each of these areas directly impact the way in which the electricity system is run as they address each of the three issues associated with wind energy stated above, respectively. It is shown that assumptions in these three areas have a large effect on the results in terms of total generation costs, wind curtailment and generator technology type dispatch. In particular accounting for these issues has resulted in wind curtailment being predicted in much larger quantities than had been previously reported. This would have a large effect on wind energy companies because it is already a very low profit margin industry. Results from this work have shown that the relaxation of system operation constraints is crucial to the economic running of the electricity system with large improvements shown in the reduction of wind curtailment and system generation costs. There are clear benefits in having a proportion of the wind installed offshore in Ireland which would help to reduce variability of wind energy generation on the system and therefore reduce wind curtailment. With envisaged future improvements in day-ahead wind forecasting from 8% to 4% mean absolute error, there are potential reductions in wind curtailment system costs and open cycle gas turbine usage. This work illustrates the consequences of assumptions in the areas of system operation constraints, onshore/offshore installed wind capacities and accuracy in wind forecasting to better inform the true costs associated with running Ireland's changing electricity system as it continues to decarbonise into the near future. This work also proposes to illustrate, through the use of Ireland as a case study, the effects that will become ever more prevalent in other synchronous systems as they pursue a path of increasing renewable energy generation.

Examining Factors Affecting Attitudes toward Nuclear Power in Taiwan

Thesis (Master's)--University of Washington, 2016-06

The exploration of consumer power in online brand communities : a comparison case study in Australia and China

Aided by the development of information technology, the balance of power in the market place is rapidly shifting from marketers towards consumers and nowhere is this more obvious than in the online environment (Denegri-Knott, Zwick, & Schroeder, 2006; Moynagh & Worsley, 2002; Newcomer, 2000; Samli, 2001). From the inception and continuous development of the Internet, consumers are becoming more empowered. They can choose what they want to click on the Internet, they can shop and transact payments, watch and download video, chat with others, be it friends or even total strangers. Especially in online communities, like-minded consumers share and exchange information, ideas and opinions. One form of online community is the online brand community, which gathers specific brand lovers. As with any social unit, people form different roles in the community and exert different effects on each other. Their interaction online can greatly influence the brand and marketers. A comprehensive understanding of the operation of this special group form is essential to advancing marketing thought and practice (Kozinets, 1999). While online communities have strongly shifted the balance of power from marketers to consumers, the current marketing literature is sparse on power theory (Merlo, Whitwell, & Lukas, 2004). Some studies have been conducted from an economic point of view (Smith, 1987), however their application to marketing has been limited. Denegri-Knott (2006) explored power based on the struggle between consumers and marketers online and identified consumer power formats such as control over the relationship, information, aggregation and participation. Her study has built a foundation for future power studies in the online environment. This research project bridges the limited marketing literature on power theory with the growing recognition of online communities among marketing academics and practitioners. Specifically, this study extends and redefines consumer power by exploring the concept of power in online brand communities, in order to better understand power structure and distribution in this context. This research investigates the applicability of the factors of consumer power identified by Denegri-Knott (2006) to the online brand community. In addition, by acknowledging the model proposed by McAlexander, Schouten, & Koenig (2002), which emphasized that community study should focus on the role of consumers and identifying multiple relationships among the community, this research further explores how member role changes will affect power relationships as well as consumer likings of the brand. As a further extension to the literature, this study also considers cultural differences and their effect on community member roles and power structure. Based on the study of Hofstede (1980), Australia and China were chosen as two distinct samples to represent differences in two cultural dimensions, namely individualism verses collectivism and high power distance verses low power distance. This contribution to the research also helps answer the research gap identified by Muñiz Jr & O'Guinn (2001), who pointed out the lack of cross cultural studies within the online brand community context. This research adopts a case study methodology to investigate the issues identified above. Case study is an appropriate research strategy to answer “how” and “why” questions of a contemporary phenomenon in real-life context (Yin, 2003). The online brand communities of “Haloforum.net” in Australia and “NGA.cn” in China were selected as two cases. In-depth interviews were used as the primary data collection method. As a result of the geographical dispersion and the preference of a certain number of participants, online synchronic interviews via MSN messenger were utilized along with the face-to-face interviews. As a supplementary approach, online observation was carried over two months, covering a two week period prior to the interviews and a six week period following the interviews. Triangulation techniques were used to strengthen the credibility and validity of the research findings (Yin, 2003). The findings of this research study suggest a new definition of power in an online brand community. This research also redefines the consumer power types and broadens the brand community model developed by McAlexander et al. (2002) in an online context by extending the various relationships between brand and members. This presents a more complete picture of how the perceived power relationships are structured in the online brand community. A new member role is discovered in the Australian online brand community in addition to the four member roles identified by Kozinets (1999), in contrast however, all four roles do not exist in the Chinese online brand community. The research proposes a model which links the defined power types and identified member roles. Furthermore, given the results of the cross-cultural comparison between Australia and China showed certain discrepancies, the research suggests that power studies in the online brand community should be country-specific. This research contributes to the body of knowledge on online consumer power, by applying it to the context of an online brand community, as well as considering factors such as cross cultural difference. Importantly, it provides insights for marketing practitioners on how to best leverage consumer power to serve brand objective in online brand communities. This, in turn, should lead to more cost effective and successful communication strategies. Finally, the study proposes future research directions. The research should be extended to communities of different sizes, to different extents of marketer control over the community, to the connection between online and offline activities within the brand community, and (given the cross-cultural findings) to different countries. In addition, a greater amount of research in this area is recommended to determine the generalizability of this study.

EMI issues in modern power electronic systems

Electromagnetic compatibility of power electronic systems becomes an engineering discipline and it should be considered at the beginning stage of a design. Thus, a power electronics design becomes more complex and challenging and it requires a good communication between EMI and Power electronics experts. Three major issues in designing a power electronic system are Losses, EMI and Harmonics. These issues affect system cost, size, efficiency and quality and it is a tradeoff between these factors when we design a power converter.

Survival Power: An Empirical Analysis of Power in a Life and Death Situation

This paper seeks to identify what antecedents of power make it more or less likely for people to survive in a life-threatening situation.In particular, we look at the Titanic disaster as the life or death situation. Maritime disasters can be interpreted as quasi-natural experiments because every person is affected by the shock. True human nature becomes apparent in such a dangerous situation. Five antecedents of power are distinguished: physical strength, economic resources, nationality, social and moral factors. This empirical analysis supports the notion that power is a key determinant in extreme situations of life or death.