Assuring Life in Composite Systems

A computational simulation method is presented to assure life in composite systems by using dynamic buckling of smart composite shells as an example. The combined use of composite mechanics, finite element computer codes, and probabilistic analysis enable the effective assessment of the dynamic buckling load of smart composite shells. A universal plot is generated to estimate the dynamic buckling load of composite shells at various load rates and probabilities. The shell structure is also evaluated with smart fibers embedded in the plies right below the outer plies. The results show that, on the average, the use of smart fibers improved the shell buckling resistance by about 9% at different probabilities and delayed the buckling occurrence time. The probabilistic sensitivities results indicate that uncertainties in the fiber volume ratio and ply thickness have major effects on the buckling load. The uncertainties in the electric field strength and smart material volume fraction have moderate effects and thereby in the assured life of the shell

Software Reliability in Semantic Web Service Composition Applications

Web Service Composition allows the development of easily reconfigurable applications that can be quickly adapted to business changes. Due to the shift in paradigm from traditional systems, new approaches are needed in order to evaluate the reliability of web service composition applications. In this paper we present an approach based on intelligent agents for semiautomatic composition as well as methods for assessing reliability. Abstract web services, corresponding to a group of services that accomplishes a specific functionality are used as a mean of assuring better system reliability. The model can be extended with other Quality of Services – QoS attributes.Software Reliability, Web Service Composition, Intelligent Agents

NASA space research and technology overview (ITP)

A series of viewgraphs summarizing NASA space research and technology is presented. Some of the specific topics covered include the organization and goals of the Office of Aeronautics and Space Technology, technology maturation strategy, integrated technology plan for the Civil Space Program, program selection and investment prioritization, and space technology benefits

Nonlinear Control of a DC MicroGrid for the Integration of Photovoltaic Panels

New connection constraints for the power network (Grid Codes) require more flexible and reliable systems, with robust solutions to cope with uncertainties and intermittence from renewable energy sources (renewables), such as photovoltaic arrays. The interconnection of such renewables with storage systems through a Direct Current (DC) MicroGrid can fulfill these requirements. A "Plug and Play" approach based on the "System of Systems" philosophy using distributed control methodologies is developed in the present work. This approach allows to interconnect a number of elements to a DC MicroGrid as power sources like photovoltaic arrays, storage systems in different time scales like batteries and supercapacitors, and loads like electric vehicles and the main AC grid. The proposed scheme can easily be scalable to a much larger number of elements.Comment: arXiv admin note: text overlap with arXiv:1607.0848

NDE: An effective approach to improved reliability and safety. A technology survey

Technical abstracts are presented for about 100 significant documents relating to nondestructive testing of aircraft structures or related structural testing and the reliability of the more commonly used evaluation methods. Particular attention is directed toward acoustic emission; liquid penetrant; magnetic particle; ultrasonics; eddy current; and radiography. The introduction of the report includes an overview of the state-of-the-art represented in the documents that have been abstracted

Ensuring Fair and Reliable Measures of Effective Teaching: Culminating Findings from the MET Project's Three-Year Study

States and districts have launched unprecedented efforts in recent years to build new feedback and evaluation systems that support teacher growth and development. The goal is to improve practice so that teachers can better help their students graduate from high school ready to succeed in college and beyond. These systems depend on trustworthy information about teaching effectiveness -- information that recognizes th complexity of teaching and is trusted by both teachers and administrators. To that end, the Measures of Effective Teaching (MET) project set out three years ago to investigate how a set of measures could identify effective teaching fairly and reliably. With the help of 3,000 teacher volunteers who opened up their classrooms to us -- along with scores of academic and organizational partners -- we have studied, among other measures:Classroom observation instruments, including both subject-specific and cross-subject tools, that define discrete teaching competencies and describe different levels of performance for each;Student perception surveys that assess key characteristics of the classroom environment, including supportiveness, challenge, and order; andStudent achievement gains on state tests and on more cognitively challenging assessments. We have reported findings as we learned them in order to provide states and districts with evidence-based guidance to inform their ongoing work. In our initial report in 2010 (Learning about Teaching), we found that a well-designed student perception survey can provide reliable feedback on aspects of teaching practice that are predictive of student learning.In 2012 (Gathering Feedback for Teaching), we presented similar results for classroom observations. We also found that an accurate observation rating requires two or more lessons, each scored by a different certified observer. With each analysis we have better understood the particular contribution that each measure makes to a complete picture of effective teaching and how those measures should be implemented to provide teachers with accurate and meaningful feedback.This final brief from the MET project's three-year study highlights new analyses that extend and deepen the insights from our previous work. These studies address three fundamental questions that face practitioners and policymakers engaged in creating teacher support and evaluation systems

Feedback for Better Teaching: Nine Principles for Using Measures of Effective Teaching

It is very hard to support effective teaching without good information about actual teaching practice. The MET project has sought to build and test measures of effective teaching so that school systems can clearly understand and then close the gap between their expectations for effective teaching and the actual teaching occurring in classrooms.But good information is hard to produce. It requires the right measures, the right measurement processes, strong communications, and an awareness of how information can be distorted. When given the right type of attention, measures can help set expectations and align effort. It will require care and attention for teacher evaluation measures to serve both professional development and accountability purposes. To help states and districts navigate the work of implementing feedback and evaluation systems that support teachers, we offer nine guiding principles based on three years' of study, observation, and collaboration with districts. Our prior reports tested, and ultimately supported, the claim that measures of teaching effectiveness could be valid and reliable. These principles, explained on the following pages, fall into three overarching imperatives, as shown in Figure 1: Measure Effective Teaching; Ensure High-Quality Data; and Invest in Improvement. Note the cyclical presentation. Well-designed evaluation systems will continually improve over time

Descentralization in education - premise of the Romanian education efficiency

Romania is far left behind in what regards education. The regular education and also the higher education are hyper centralized. The chronic sub finance is built into a subject of permanent political dispute. In the latest years there have been made important steps to assure the quality of education, for descentralization and to create a modern institutional medium in education, but to few measures are applied.education, descentralization, efficiency, human resources