892 resultados para high-stakes test
Resumo:
The purpose of this study was to analyze the evolution of Florida state level policy efforts and to assess the responding educational policy development and implementation at the local school district level. The focus of this study was the secondary language arts curriculum in Miami-Dade County Public Schools. Data was collected using document analysis as a source of meaning making out of the language sets proffered by agencies at each level. A matrix was created based on Klein's levels of curriculum decision-making and Functional Process Theory categories of policy formation. The matrix allowed the researcher to code and classify specific information in terms accountability/high-stakes testing; authority; outside influences; and operational/structural organization. Federal policy documents provided a background and impetus for much of what originated at the State level. The State then produced policy directives which were accepted by the District and specific policy directives and guidelines for practice. No evidence was found indicating the involvement of any other agencies in the development, transmission or implementation of the State level initiated policies. After analyzing the evolutionary process, it became clear that state policy directives were never challenged or discussed. Rather, they were accepted as standards to be met and as such, school districts complied. Policy implementation is shown to be a top-down phenomenon. No evidence was found indicating a dialogue between state and local systems, rather the state, as the source of authority, issued specifically worded policy directives and the district complied. Finally, this study recognizes that outside influences play an important role in shaping the education reform policy in the state of Florida. The federal government, through NCLB and other initiatives created a climate which led almost naturally to the creation of the Florida A+ Plan. Similarly, the concern of the business community, always interested in the production of competent workers, continued to support efforts at raising the minimum skill level of Florida high school graduates. Suggestions are made for future research including the examination of local school sites in order to assess the overall nature of the school experience rather than rely upon performance indicators mandated by state policy.
Resumo:
The purpose of this study was to ascertain the perceptions of educators at one elementary school regarding the changes in the teaching and learning environment and their related effects following the implementation of Florida's A+ high-stakes accountability system. This study also assessed whether these changes were identified by participants as meaningful and enduring, in terms of the definition by Lieberman and Miller (1999). Twenty-one educators, including 17 teachers and four administrators, at Blue Ribbon Elementary school were interviewed. Data were inductively coded and categorized into four major themes: (a) teaching and learning environment consistency, (b) changes in the teaching and learning environment since the implementation of A+, (c) effects of the changes, and (d) significant and enduring change. Findings fell into three categories (a) identified changes since A+ implementation, (b) effects of changes, and (c) what participants believed was significant and long term change, which included those characteristics of the school that had been identified as consistent in the teaching and learning environment. Statements of the participants explained their perceptions about what instructional decisions where made in response to the A+ Plan including the modification of curriculum, the addition or omission of subject matter taught, and the positive or negative impact these decisions had on the teaching and learning environment. It was found that study participants felt all changes and their effects were a direct result of the A+ Plan and viewed many of the changes as being neither significant nor long term Analysis of the educators' perceptions of the changes they experienced revealed the overall feeling that the changes were not indicative of what was necessary to make a school successful. For the participants, the changes lacked the characteristics that they had described as vital in what constituted success. This led to the conclusion that, by Lieberman and Miller's definition, the majority of changes and effects that were implemented at the school as a result of the mandated A+ Plan, were not meaningful and enduring for effective school reform.
Resumo:
The principalship has changed significantly over the past 20 years. Today’s principals must be effective instructional leaders, managers of large facilities, and experts at analyzing data to successfully meet the accountability demands of high-stakes testing, along with state, and federal mandates. The primary purpose of this quantitative study was to examine how 43 first- and second-year sitting school principals perceived their mentoring experiences and the degree to which a principal mentoring program—offered by their large urban school district—was effective in building their leadership capacity. A second purpose of this inquiry was to understand these principals’ perceptions of the most beneficial aspects of the mentoring program. The study used quantitative data gathered via an online questionnaire distributed during Fall 2015. The results indicated that respondents perceived that the components of the large urban school-mentoring program were generally effective in training principal mentees to become highly-effective school leaders. This study enriches the literature on mentoring by providing the voices of first and second year school leaders to add depth to the characteristics of successful mentoring programs.
Resumo:
This thesis examines the ways in which linguistic minority students assert themselves as rhetorical agents when faced with the expectation of impromptu verbal responses. Based on a study that aims at identifying specific rhetorical strategies these students employ, the goal of this thesis is to theorize ways in which linguistic minorities deal with the challenges of fast-paced, high-stakes interactions. The practices that emerge from data analysis suggest that such strategies tend to be reactive rather than proactive and highly dependent on context. While they are valuable ways for linguistic minorities to navigate their ways in specific moments, the thesis argues that they are ultimately insufficient to create a sense of agency and empowerment. Future research hence needs to address ways in which strategies can be consciously trained and employed in order to create a more inclusive classroom experience for linguistic minority students.
Resumo:
The preventive maintenance of traction equipment for Very High Speed Trains (VHST) nowadays is becoming very expensive owing to the high complexity and quality of these components that require high reliability. An efficient maintenance approach like the Condition-Based Maintenance (CBM) should be implemented to reduce the costs. For this purpose, an experimental full-scale test rig for the CBM of VHST traction equipment has been designed to investigate in detail failures in the main mechanical components of system, i.e. motor, bearings and gearbox. The paper describes the main characteristics of this unique test rig, able to reproduce accurately the train operating conditions, including the relative movements of the motor, the gearbox and the wheel axle. Gearbox, bearing seats and motor are equipped by accelerometers, thermocouples, torque meter and other sensors in different positions. The testing results give important information about the most suitable sensor position and type to be installed for each component and show the effectiveness of the techniques used for the signal analysis in order to identify faults of the gearbox and motor bearings.
Resumo:
Before installation, a voltage source converter is usually subjected to heat-run test to verify its thermal design and performance under load. For heat-run test, the converter needs to be operated at rated voltage and rated current for a substantial length of time. Hence, such tests consume huge amount of energy in case of high-power converters. Also, the capacities of the source and loads available in the research and development (R&D) centre or the production facility could be inadequate to conduct such tests. This paper proposes a method to conduct heat-run tests on high-power, pulse width modulated (PWM) converters with low energy consumption. The experimental set-up consists of the converter under test and another converter (of similar or higher rating), both connected in parallel on the ac side and open on the dc side. Vector-control or synchronous reference frame control is employed to control the converters such that one draws certain amount of reactive power and the other supplies the same; only the system losses are drawn from the mains. The performance of the controller is validated through simulation and experiments. Experimental results, pertaining to heat-run tests on a high-power PWM converter, are presented at power levels of 25 kVA to 150 kVA.
Resumo:
Semiconductor device junction temperatures are maintained within datasheet specified limits to avoid failure in power converters. Burn-in tests are used to ensure this. In inverters, thermal time constants can be large and burn-in tests are required to be performed over long durations of time. At higher power levels, besides increased production cost, the testing requires sources and loads that can handle high power. In this study, a novel method to test a high power three-phase grid-connected inverter is proposed. The method eliminates the need for high power sources and loads. Only energy corresponding to the losses is consumed. The test is done by circulating rated current within the three legs of the inverter. All the phase legs being loaded, the method can be used to test the inverter in both cases of a common or independent cooling arrangement for the inverter phase legs. Further, the method can be used with different inverter configurations - three- or four-wire and for different pulse width modulation (PWM) techniques. The method has been experimentally validated on a 24 kVA inverter for a four-wire configuration that uses sine-triangle PWM and a three-wire configuration that uses conventional space vector PWM.
Resumo:
The effects of the free-stream thermo-chemical state on the test model flow field in the high-enthalpy tunnel are studied numerically. The properties of the free-stream, which is in thermo-chemical non-equilibrium, are determined by calculating the nozzle flow field. A free-stream with total enthalpy equal to the real one in the tunnel while in thermo-chemical equilibrium is constructed artificially to simulate the natural atmosphere condition. The flow fields over the test models (blunt cone and Apollo command capsule model) under both the non-equilibrium and the virtual equilibrium free-stream conditions are calculated. By comparing the properties including pressure, temperature, species concentration and radiation distributions of these two types of flow fields, the effects of the non-equilibrium state of the free-stream in the high-enthalpy shock tunnel are analyzed.
Resumo:
Two shock-capturing methods are considered. One is based on a standard conservative Roe scheme with van Leer's MUSCL variable extrapolation method applied to characteristic variables and a Runge-Kutta time stepping scheme. The other is based on the novel CABARET space-time scheme, which uses two sets of staggered variables, one for the conservation step and the other for characteristic splitting into local Riemann invariants. The methods are compared in a range of 2-D inviscid compressible flow test cases. Copyright © 2008 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
Resumo:
This paper presents measurement methods for determining the reflection coefficients and frequency responses of semiconductor laser diodes, photodiodes, and EA modulator chips. A novel method for determining the intrinsic frequency responses of laser diodes is also proposed, and applications of the developed measurement methods are discussed. We demonstrate the compensation of bonding wire on the capacitances of both the submount and the laser diode, and present a method for estimating the potential modulation bandwidth of TO packaging technique. Initial study on removing the effects of test fixture on large-signal performances of optoelectronic devices at high data rate is also given.
Resumo:
El objetivo de este artículo es determinar si el incremento en la tasa de desempleo tiene algún efecto sobre la tasa de divorcios. Con este fin se utilizan series de tiempo y datos de corte transversal para Japón. También se incluyen la tasa de crimenes y el promedio de las horas trabajadas como variables explicativas. Adicionalmente se efectúa análisis de cointegración con el fin de evitar relaciones espúreas entre las series de tiempo. Los resultados sugieren que existe una correlación positiva entre la tasa de desempleo y la tasa de divorcios. También confirmamos que existe una relación cronológica cercana entre el desempleo y el divorcio.