Physics-based modeling of power system components for the evaluation of low-frequency radiated electromagnetic fields

The low-frequency electromagnetic compatibility (EMC) is an increasingly important aspect in the design of practical systems to ensure the functional safety and reliability of complex products. The opportunities for using numerical techniques to predict and analyze system's EMC are therefore of considerable interest in many industries. As the first phase of study, a proper model, including all the details of the component, was required. Therefore, the advances in EMC modeling were studied with classifying analytical and numerical models. The selected model was finite element (FE) modeling, coupled with the distributed network method, to generate the model of the converter's components and obtain the frequency behavioral model of the converter. The method has the ability to reveal the behavior of parasitic elements and higher resonances, which have critical impacts in studying EMI problems. For the EMC and signature studies of the machine drives, the equivalent source modeling was studied. Considering the details of the multi-machine environment, including actual models, some innovation in equivalent source modeling was performed to decrease the simulation time dramatically. Several models were designed in this study and the voltage current cube model and wire model have the best result. The GA-based PSO method is used as the optimization process. Superposition and suppression of the fields in coupling the components were also studied and verified. The simulation time of the equivalent model is 80-100 times lower than the detailed model. All tests were verified experimentally. As the application of EMC and signature study, the fault diagnosis and condition monitoring of an induction motor drive was developed using radiated fields. In addition to experimental tests, the 3DFE analysis was coupled with circuit-based software to implement the incipient fault cases. The identification was implemented using ANN for seventy various faulty cases. The simulation results were verified experimentally. Finally, the identification of the types of power components were implemented. The results show that it is possible to identify the type of components, as well as the faulty components, by comparing the amplitudes of their stray field harmonics. The identification using the stray fields is nondestructive and can be used for the setups that cannot go offline and be dismantled

Household Preferences for Financing Hurricane Risk Mitigation: A Survey Based Empirical Analysis

After a series of major storms over the last 20 years, the state of financing for U.S. natural disaster insurance has undergone substantial disruptions causing many federal and state backed programs against residential property damage to become severally underfunded. In order to regain actuarial soundness, policy makers have proposed a shift to a system that reflects risk-based pricing for property insurance. We examine survey responses from 1394 single-family homeowners in the state of Florida for support of several natural disaster mitigation policy reforms. Utilizing a partial proportional odds model we test for effects of location, risk perception, socio-economic and housing characteristics on support for policy reforms. Our findings suggest residents across the state, not just risk-prone homeowners, support the current subsidized model. We also examine several other policy questions from the survey to verify our initial results. Finally, the implications of our findings are discussed to provide inputs to policymakers.

Estimulação transcraniana por corrente contínua (ETCC) sobre o córtex motor na modulação autonômica em pessoas com lesão medular com diferentes graus e níveis de lesão

Introduction: Transcranial Direct Current Stimulation (tDCS) has been used in studies for the treatment of chronic pain, but their effects on the autonomic nervous system (ANS) are non-existent. Therefore, the need for studies is of fundamental importance, as these individuals have autonomic imbalance and the intensity of this is dependent on the degree and level of injury. Objective: We investigated the effect of tDCS on the ANS in people with spinal cord injury (SCI) with different degrees and levels of injury. Methods: Randomized, placebo-controlled, double-blind, applied anodal tDCS or sham on the primary motor cortex (M1), bilaterally. The subjects (lower incomplete injury, n = 7; lower complete injury, n = 9; and high complete thoracic injury, n = 3) visited the laboratory three times and received active or sham tDCS for 13min. The heart rate variability (HRV) was measured before, during and after stimulation and analyzed the variables LF, HF and LF / HF. Results: The tDCS modulated the ANS in different ways among the groups. In individuals with SCI high complete thoracic the tDCS did not change the HRV. However, for individuals with SCI low incomplete, tDCS changed the HRV in order to increase sympathetic (LF, p = 0.046) and reduced parasympathetic (HF, p = 0.046). For individuals SCI low complete to tDCS changed the HRV reduction sympathetic (LF, p = 0.017) and increased parasympathetic (HF, p = 0.017). Conclusions: The present study suggests that anodal tDCS applied on the motor cortex bilaterally could modulate the ANS balance in people with spinal cord injury and that this effect is dependent on the degree and level of injury.

Physical oceanography during POLARSTERN cruise ANT-V/3

The work carried out by the physical oceanography group on POLARSTERN Leg ANT-V/3 concentrated on four major topics: A. A large scale survey of the eastern boundary between the Weddell gyre and the open ocean. On the way to the coastal polynya in early October 12 CTD stations were carried out between 54°30'S, 6°E and 70°30'S 8°W. Another set of 16 stations was obtained in early December on the way back north. During this transsect three current meter moorings were recovered at Maud Rise. The path between the current meter arrays was used to run an additional section to the NNE across the top of Maud Rise. B. A large scale survey of the Antarctic Coastal Current along the eastern shelf area. To obtain the water mass characteristics along the eastern Weddell shelf 36 CTD stations were carried out between Atka Bay and the Filchner Trench. Most of the stations were located on the shelf. Cross shelf sections were obtained both near Drescher Inlet and off Halley Bay, in the divergence area of the Coastal Current where the continental slope turns to the west and south of Vestkapp at Neptune's Point. A longshore section over 120 km was run north of Vestkapp. C. A mesoscale survey of the Antarctic Coastal Current off Drescher Inlet. The experimental work consisted of 37 CTD-stations and direct current measurements. The CTD-profiles were grouped into seven sections perpendicular to the coast line off Drescher Inlet extending once over 70 km but normally over 35 km. The profile depth ranged from 300 m on one section to the complete water column at two sections. Most sections consist of five stations providing highest resolution over the upper continental slope with offshore increasing spacing. The stations were chosen to represent the shelf (450 m), the shelf break (800 m), the upper slope (1600 m), the lower slope (2400 m) and the transition to the abyssal plain (3400 m). Rough topography and difficult ice conditions made it impossible to meet those requirements in all cases. D. A small scale survey of the hydrographic conditions under the sea ice. The motivation for these studies arose during the cruise. Consequently a suitable Instrumentation had to be developed at sea. This was done with a NB-Smart CTD which was inserted on an L-shaped lever through a hole in the ice. However, various water intrusions into the instrument resulted in the failure of this technique. In consequence a special lever system was built to position a NB Mark 3b weighing about 40 kg below the ice. Twenty four profiles were obtained reaching from the bottom of the ice down to 2 m below the ice surface with a maximum distance of 1 m from the entry hole. As the conductivity sensor was influenced by nearby ice platelets, salinity samples where drawn to check the sensor.

A concepção de trabalho escolar a partir de Maurício Tragtenberg: fios e tramas de debate na (des)politização dos sujeitos sociais

This thesis, part of the research line "Work, Society and Education" analyzes, in a dialectical perspective, in the light of Tragtenberg´s studies, the conception of subject of schoolwork, considering the organization and the complexity of this context and inviting the investigative gaze. Our hypothesis is that the workers of education have, in the schoolwork, a fragile politicization field and overcoming the installed model, accepting themselves as executers with self-organizing difficulties, distanced from the effective participation, autonomy and self-management. We consider studies on the logic of the work, believing that the understanding of schoolwork is constitute into the current societal model, in whom its bureaucratic and hierarchical matrix, linked to articulated / articulators of the dominant socio-economic class interests. Scholars such as Braverman, Frigotto and Tragtenberg, among others, are important contributions to this reflection. We have analyzed the logic of the work also in dialogue with pedagogies differentiated, among them, the Libertarian defended by Tragtenberg, aiming to understand the conceptions and practices of the subjects involved. We accomplished a bibliographical critical analysis, in a dialectical character, focusing on the categories: work, schoolwork, control, autonomy and self-management, in order to understand the complexity of the praxis in study, dialoguing with the pillars categories historicity, contradiction and totality, which transversalize the developed analysis. The consideration of these concepts allows us to uncover the dominant bureaucratic structure and its possible overcoming fields. We believe contribute to problematizing and proposers studies, reflections and discussions, strengthening debates, deconstructing naturalizations and contributing to the political process of the subjects.

Mock-ups in design : the implications of utlizing [sic] a mock-up review process in professional practice

The purpose of this research is to examine the use of a mock-up review process in interior design projects to better understand the implications of using such a process within the standard professional practice model. The research consisted of interviewing design professionals who utilize mock-ups as part of their standard of practice. These interviews were centered around two groups - those working in shipbuilding, where mock-ups have a long history, and those working in land-based projects, where mock-up use is rare. Analysis of the interviews indicated a positive relationship between mock-up use and collaboration, innovation, and problem solving. The interviews also brought to light concerns on behalf of all the professionals surveyed about the current practice model in land-based building design and construction projects within the United States. The positive relationships shown in the thesis support further research to explore how mock-ups can be best utilized in interior design.

Depth, age, strontium isotopic ratios and trace elemental ratios of samples from thirteen DSDP and ODP holes

Large variations exist between published mid-Cretaceous (late Barremian to early Turonian stages) seawater Sr-isotope stratigraphies; this has resulted in disparate interpretations of crustal production rates. We report on a detailed investigation of seawater Sr-isotope stratigraphy based on foraminifers and, where available, on inoceramid bivalves from 12 mid-Cretaceous Deep Sea Drilling Project and Ocean Drilling Program sections. The effects of diagenesis are assessed using scanning electron microscope observations and trace-elemental analyses, but are best distinguished by comparing the 87Sr/86Sr values of similar-age samples from different sites. Strontium-isotope analyses compiled from 9 of 12 sites that have detailed age control define one band of common values. This band is used as a composite curve, which presumably represents seawater 87Sr/86Sr values. The composite curve shows a "trough" of markedly lower 87Sr/86Sr values in the Aptian and early Albian stages, higher but constant values for the middle Albian-Cenomanian stages, followed by a decrease in 87Sr/86Sr values in the early Turonian. Variations between published mid-Cretaceous Sr-isotope records result from diagenetic alteration, analytical problems, and the diverse biostratigraphic approaches and assumptions used to estimate sample ages. When preexisting age data are made consistent, the composite record shows close similarities with data sets derived from measurements of macrofossils in land sections of Europe and North America. The interval of decreased 87Sr/86Sr values in the Aptian-Albian stages overlaps with the pulse of mid-plate volcanic activity that produced the Ontong Java, Manihiki, and Kerguelen Plateaus. The exact age and the shape of the trough, however, are consistent with increased spreading rates at oceanic ridges, given the existing data on the timing of mid-plate volcanic activity.

Differential contributions of the mIPS and PMd in the movement planning of reaches investigated through HD-tDCS

To reach for a target, we must formulate a movement plan - a difference vector of the target position with respect to the starting hand position. While it is known that the medial part of the intraparietal sulcus (mIPS) and the dorsal premotor (PMd) activity reflects aspects of a kinematic plan for a reaching movement, it is unclear whether or how the two regions may differ. We investigated the functional roles of the mIPS and PMd in the planning of reaching movements using high definition transcranial direct current stimulation (HD-tDCS) and examined changes in horizontal endpoint error when participants were subjected to anodal and cathodal stimulation. The left mIPS and PMd were functionally localized with fMRI in each participant using an interleaved center-out pointing and saccade task and mapped onto the scalp using Brainsight. We adopted a randomized, single-blind design and applied anodal and cathodal stimulation (2mA for 20 min; 3cm radius 4x1 electrode placement) during 4 separate visits scheduled at least a week apart. Each participant performed 250 baseline, stimulation, and post-stimulation memory-guided reaches starting from one of two initial hand positions (IHPs) to one of 4 briefly flashed targets (20 cm distant, 5 cm apart horizontally) while fixating on a straight-ahead cross located at the target line. Separate 2-way repeated measures ANOVAs of horizontal endpoint error difference after cathodal tDCS at each stimulation site revealed a significant IHP by target position interaction effect at the left mIPS, and significant IHP and target main effects at the left PMd. Behaviorally, these effects corresponded to IHP-dependent contractions after cathodal mIPS tDCS and IHP-independent contractions after cathodal PMd tDCS. These results suggest that the movement vector is not yet formed at the input level of mIPS, but is encoded at the input of PMd. These results also indicate that tDCS is a viable, useful method in investigating movement planning properties through temporary perturbations of the system.

Karst hazard analysis towards the development of predictive karst models for southern Ontario

An investigation into karst hazard in southern Ontario has been undertaken with the intention of leading to the development of predictive karst models for this region. The reason these are not currently feasible is a lack of sufficient karst data, though this is not entirely due to the lack of karst features. Geophysical data was collected at Lake on the Mountain, Ontario as part of this karst investigation. This data was collected in order to validate the long-standing hypothesis that Lake on the Mountain was formed from a sinkhole collapse. Sub-bottom acoustic profiling data was collected in order to image the lake bottom sediments and bedrock. Vertical bedrock features interpreted as solutionally enlarged fractures were taken as evidence for karst processes on the lake bottom. Additionally, the bedrock topography shows a narrower and more elongated basin than was previously identified, and this also lies parallel to a mapped fault system in the area. This suggests that Lake on the Mountain was formed over a fault zone which also supports the sinkhole hypothesis as it would provide groundwater pathways for karst dissolution to occur. Previous sediment cores suggest that Lake on the Mountain would have formed at some point during the Wisconsinan glaciation with glacial meltwater and glacial loading as potential contributing factors to sinkhole development. A probabilistic karst model for the state of Kentucky, USA, has been generated using the Weights of Evidence method. This model is presented as an example of the predictive capabilities of these kind of data-driven modelling techniques and to show how such models could be applied to karst in Ontario. The model was able to classify 70% of the validation dataset correctly while minimizing false positive identifications. This is moderately successful and could stand to be improved. Finally, suggestions to improving the current karst model of southern Ontario are suggested with the goal of increasing investigation into karst in Ontario and streamlining the reporting system for sinkholes, caves, and other karst features so as to improve the current Ontario karst database.

Integración de aerogeneradores de baja potencia en la red de baja tensión

[EN] The current energy model is unsustainable economically, environmentally and socially forcing develop renewable technologies that modify the concept to the responsible use. The use of low-power wind turbines has generally been limited to isolated which has slowed their development systems. The study addresses this technological niche to deepen their study of integration of electricity on a low voltage network. For this first wind potential with Homer software is evaluated. Various scenarios are simulated in "The IEEE European Test Low Voltage Feeder" network using the software OpenDSS widely used in studies of Generation Distributed by EPRI (Electric Power Research Institute).

BETA-GA2O3: A TRANSPARENT CONDUCTIVE OXIDE FOR POTENTIAL RESISTIVE SWITCHING APPLICATIONS

Thesis (Ph.D.)--University of Washington, 2016-08

Health assets and active lifestyles during preadolescence and adolescence: highlights from the HBSC/WHO health survey and implications for health promotion

The present chapter discusses the assets model as a theoretical approach to the study of health behavior and health promotion. The model emphasizes people’s talents, competences, and resources. In this chapter, a health asset is defined as any factor or resource that maximizes the opportunities for individuals, local communities, and populations to attain and maintain health and well-being. This perspective expands and complements the current medical model as it focuses on the development of a sense of empowerment in community members to prevent and manage their own health. Therefore, in this chapter we address the concepts of salutogenesis, social support, resilience, coping, self-regulation, social capital, and personal and social competence, which are central to the development of individuals’ potential to manage and savor their own health, creating the conditions for self-fulfillment. Additionally, we demonstrate how the assets model guides the study of children’s and adolescents’ health in the Portuguese Health Behaviour in School-aged Children study (www.hbsc.org), concentrating on areas such as active lifestyles and quality-of-life perception. Finally, we present a roadmap for action that emphasizes the need to identify the factors that make children and adolescents happy and healthy individuals, while minimizing risks and problems they naturally encounter throughout their development. We also argue for the need to involve young people in discussions concerning their health and health promotion practices, focusing on the development of talents, capabilities, and positive expectations for the future.

Importancia del “efecto rebote” o paradoja de Jevons en el diseño de la política ambiental

En este artículo de reflexión, se analiza el diseño actual de las políticas ambientales en Colombia, las cuales se han centrado principalmente en el aprovechamiento de los recursos naturales como fuentes de materiales y energía para generar crecimiento económico. En este sentido, es evidente que la preocupación colectiva por el manejo de la oferta ambiental, como base para el desarrollo sostenible establecido en la Constitución, no ha logrado implementarse de forma efectiva, principalmente por el enfoque reactivo y coercitivo de las políticas y normativas vigentes, aunadas a un escaso fomento para la transformación del estilo de vida consumista nacional, situación que ha generado un efecto rebote incrementando los niveles de uso y consumo de los recursos naturales (especialmente de los denominados no renovables) y limitado la eficiencia energética; por ejemplo, esto puede observarse en el sector minero-energético nacional. Considerando que existe una preocupación global por la sostenibilidad, es necesario que el diseño de las políticas ambientales nacionales se aleje del optimismo económico y tecnológico del modelo económico vigente e incorpore, de forma cierta en sus políticas, estrategias que permitan equilibrar las relaciones de oferta y demanda de los servicios ambientales que sustentan el desarrollo nacional, alentando, al tiempo, el consumo responsable de la población colombiana, además de atender las iniciativas comunitarias de regulación e inclusión social en el manejo de los bienes y servicios ambientales para generar procesos de sostenibilidad fuerte.

A avaliação de desempenho docente vista por professores: realidades, expetativas, desafios e oportunidades

A avaliação de desempenho docente tem sido considerada o alfa e o ômega dos sistemas educativos, nas últimas décadas. Em Portugal, desde 2007, esta questão tornou-se mais acutilante devido às alterações introduzidas no Estatuto da Carreira Docente que originaram uma alteração profunda nas práticas de avaliação do desempenho docente. A implementação do novo modelo despoletou forte resistência por parte destes profissionais, alimentada por uma base concetual distante da realidade das escolas portuguesas e por tibiezas na execução do processo de avaliação. O principal objetivo deste estudo consistiu em apresentar os contributos de professores para um modelo de avaliação do desempenho docente, assumindo as expetativas e as perceções destes profissionais como referente imprescindível para a sustentabilidade avaliativa do modelo. Para além disso, procedeu-se a uma breve descrição e avaliação do modelo de avaliação docente, implementado entre 2007 e 2011, recuperando perceções depuradas pelo tempo. O estudo, descritivo e inferencial, conciliou abordagens de natureza quantitativa e qualitativa, tendo recorrido a um questionário, aplicado a 585 docentes em funções no Algarve, e à entrevista, realizada a quatro informadores privilegiados do processo avaliativo. Os resultados alcançados apontaram para i) de um conjunto de pareceres favoráveis face a alguns aspetos do modelo de avaliação vigente entre 2007 e 2011; ii) uma avaliação globalmente negativa do mesmo modelo, iii) a definição de componentes das diferentes dimensões de modelo avaliativo, onde se identificou a preponderância da vertente formativa; a articulação da avaliação dos docentes com a avaliação de escola e com outros documentos de gestão escolar; a coincidência dos ciclos avaliativos com a progressão na carreira; a autoavaliação como principal instrumento de recolha de dados; a observação facultativa de aulas; a existência de avaliadores com formação em supervisão ou avaliação e capacitados com um perfil adequado; e o uso dos resultados da avaliação para a melhoria das práticas letivas e para a progressão na carreira, sendo ainda de considerar a possibilidade de acionar mecanismos de recuperação, caso existissem indicadores de insucesso na prática profissional do docente. O estudo termina com o enunciado de recomendações para a reconceptualização do modelo de avaliação dos docentes, permitindo reconhecer e eliminar os fatores conflituantes, tendo em vista a concretização da avaliação docente como estratégia impulsionadora da melhoria do desempenho dos professores, da escola e do sistema educativo. Palavras-chave: avaliação educacional; avaliação de desempenho docente; modelos de avaliação de desempenho docente; desenvolvimento profissional do professor, educadores e professores dos ensinos básico e secundário; ABSTRACT:Teacher performance appraisal has been considered the alpha and omega of educational systems in recent decades. In Portugal, since 2007, this issue has become more incisive due to amendments to the Teaching Career Statute that brought deep changes in assessment practices of teacher performance. The application of the new system has triggered strong resistance by these professionals, powered by a distant conceptual basis of the reality of Portuguese schools and weaknesses in the implementation of the appraisal process. The aim of this study is to present the teachers contributions to this teacher performance appraisal model, taking the expectations and perceptions of these professionals as an essential reference for the sustainability of the appraisal process. In addition, a brief description and evaluation of the teacher performance appraisal model, implemented between 2007 and 2011, was given, recovering perceptions filtered by time. The study, descriptive and inferential, reconciled quantitative and qualitative approaches, has used a questionnaire applied to 585 teachers serving on the Algarve, and an interview to four held key informants of the teacher appraisal process. The achieved results showed i) a set of favorable opinions about some aspects of the current evaluation model between 2007 and 2011; ii) a generally negative evaluation of the same model, iii) the definition of components of different dimensions of the appraisal system, which showed preponderance of formative purposes; the joint assessment of teachers with school evaluation and other school management documents; the coincidence of the evaluation cycles with career advancement; self-evaluation as the main data collection instrument; the optional classroom observation; the existence of evaluators under supervision in training or evaluation and empowered with the right profile; and the use of evaluation results to improve teaching practices and to career advancement, still considering the possibility of using recovery mechanisms if there were failure indicators in professional teaching practice. The study ends with the statement of recommendations for the reconceptualization of teacher performance appraisal, which allowed to recognize and eliminate conflicting factors, with a view to implementing the teaching appraisal as a compelling strategy for improving teacher performance, school and educational system. Keywords: educational evaluation; teacher performance appraisal; teacher performance appraisal systems; teacher professional development; early years teachers, primary and secondary school teachers.