An evaluation of a group of exercises in reading prepared for slow learning children in the primary grades

Thesis (M.Ed.)--Boston Universit

The vibrations induced by surface irregularities in road pavements – a Matlab® approach

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Correction to: The vibrations induced by surface irregularities in road pavements – a Matlab® approach

After publication of this article [1], it is noticed the article contained an error with eq. 12, the c s should be squared. The correct eq. 12 is provided below

Advanced Satellite Technique for Volcanic Activity Monitoring and Early Warning.

Nowadays, satellite remote sensing is an important tool for volcanic activity monitoring, thanks to several operational satellite platforms providing data everywhere with high observational frequencies and generally at low cost. Among different techniques available, an advanced satellite method, named RST (Robust Satellite Technique). based on the multitemporal analysis of satellite data, has shown a high capability in volcanic activity monitoring. This approach has proved capable of identifyimg and tracking volcanic ash Cloud and of correctly detecting and monitoring volcanic thermal anomalies. This paper analyzes some recent results, obtained applying this approach to the last eruptive events of Mt. Etna using both polar and geostationary satellites. In particular, for the first time, this approach is implemented on the present geostationary platform MSG-SEVIRI, with 15 min of temporal resolution. Preliminary results, together with a future potential of this implementation, are shown and discussed. Moreover, a differential RST index in time domain is also proposed for near real-time application, as a possible contribution to the development of an efficient early warning satellite system for volcanic hazard mitigation

Impact localization on a composite tail rotor blade using an inverse filtering approach

This article presents an in situ structural health monitoring imaging system for the localization of impacts on a composite complex structure such as a tail rotor blade. Unlike conventional plate-like panels, this composite structure presents a strong anisotropy and inhomogeneous elastic nature due to the presence of both glass fibre and carbon fibre, a geometrically complex shape due to the curvature of the blade’s airfoil section and variations in the mechanical behaviour due to local changes in the thickness. The proposed imaging technique is based on the inverse filtering or reciprocal time reversal approach applied to the waveforms originated from a point of the structure of unknown location (impact source) and a number of signals stored in a database containing the experimental Green’s function of the medium. Unlike other ultrasonic impact localization methods, the present technique allows achieving the optimal focalization of the impact point in the spatial and time domain, by taking advantage of multiple linear scattering and a small number of receiver sensors

Advanced satellite technique for volcanic activity monitoring and early warning

Nowadays, satellite remote sensing is an important tool for volcanic activity monitoring, thanks to several operational satellite platforms providing data everywhere with high observational frequencies and generally at low cost. Among different techniques available, an advanced satellite method, named RST (Robust Satellite Technique), based on the multitemporal analysis of satellite data, has shown a high capability in volcanic activity monitoring. This approach has proved capable of identifying and tracking volcanic ash cloud and of correctly detecting and monitoring volcanic thermal anomalies. This paper analyzes some recent results, obtained applying this approach to the last eruptive events of Mt. Etna using both polar and geostationary satellites. In particular, for the first time, this approach is implemented on the present geostationary platform MSG-SEVIRI, with 15 min of temporal resolution. Preliminary results, together with a future potential of this implementation, are shown and discussed. Moreover, a differential RST index in time domain is also proposed for near real-time application, as a possible contribution to the development of an efficient early warning satellite system for volcanic hazard mitigation

Advanced turboprop multidisciplinary design and optimization within agile project

The present paper deals with the design, analysis and optimization of a 90 passengers turboprop aircraft with a design range of 1200 nautical miles and a cruise Mach number equal to 0.56. The prescribed aircraft is one of the use cases of the AGILE European project, aiming to provide a 3rd generation of multidisciplinary design and optimization chain, following the collaborative and remote aircraft design paradigm, through an heterogenous team of experts. The multidisciplinary aircraft design analysis is set-up involving tools provided by AGILE partners distributed worldwide and run locally from partners side. A complete design of experiment, focused on wing planform variables, is performed to build response surfaces suitable for optimization purposes. The goal of the optimization is the direct operating cost, subject to wing design variables and top-level aircraft requirements

Gamification techniques for raising cyber security awareness

Due to the prevalence of online services in modern society, such as internet banking and social media, it is important for users to have an understanding of basic security measures in order to keep themselves safe online. However, users often do not know how to make their online interactions secure, which demonstrates an educational need in this area. Gamification has grown in popularity in recent years and has been used to teach people about a range of subjects. This paper presents an exploratory study investigating the use of gamification techniques to educate average users about password security, with the aim of raising overall security awareness. To explore the impact of such techniques, a role-playing quiz application (RPG) was developed for the Android platform to educate users about password security. Results gained from the work highlightedthat users enjoyed learning via the use of the password application, and felt they benefitted from the inclusion of gamification techniques. Future work seeks to expand the prototype into a full solution, covering a range of security awareness issues

A model-based rams estimation methodology for innovative aircraft on-board systems supporting mdo applications

The reduction of aircraft operating costs is one of the most important objectives addressed by aeronautical manufactures and research centers in the last decades. In order to reach this objective, one of the current ways is to develop innovative on-board system architectures, which can bring to lower fuel and maintenance costs. The development and optimization of these new aircraft on-board systems can be addressed through a Multidisciplinary Design Optimization (MDO) approach, which involves different disciplines. One relevant discipline in this MDO problem is Reliability, Availability, Maintainability and Safety (RAMS), which allows the assessment of the reliability and safety of aircraft systems. Indeed the development of innovative systems cannot comply with only performance requirements, but also with reliability and safety constraints. Therefore, the RAMS discipline plays an important role in the development of innovative on-board systems. In the last years, different RAMS models and methods have been defined, considering both conventional and innovative architectures. However, most of them rely on a document-based approach, which makes difficult and time consuming the use of information gained through their analysis to improve system architectures. On the contrary, a model-based approach would make easier and more accessible the study of systems reliability and safety, as explained in several studies. Model Based Systems Engineering (MBSE) is an emerging approach that is mainly used for the design of complex systems. However, only a few studies propose this approach for the evaluation of system safety and reliability. The aim of this paper is therefore to propose a MBSE approach for model-based RAMS evaluations. The paper demonstrates that RAMS models can be developed to quickly and more effectively assess the reliability and safety of conventional and innovative on-board system architectures. In addition, further activities for the integration of the model-based RAMS methodology within MDO processes are described in the paper

ASSESSMENT OF NEW TECHNOLOGIES IN A MULTI-DISCIPLINARY DESIGN ANALYSIS AND OPTIMIZATION ENVIRONMENT INCLUDING RAMS AND COST DISCIPLINES

The aim of the present paper is to assess the effect of new technologies on the whole aircraft product including its costs, reliability and maintainability characteristics. Several studies have been conducted dealing with the preliminary evaluation of Reliability, Availability, Maintainability and Safety (RAMS) of conventional aircraft. They provide a very effective method to preliminary estimate RAMS characteristics but their employment is not completely suitable for the analysis of unconventional configurations adopting new technologies. This paper aims at evaluating how the aircraft costs and RAMS characteristics are affected by new structures material, natural laminar flow wing technology and unconventional actuator system (electro-hydrostatic actuators), hence an update of the state of the art models is needed. This evaluation is performed by means of a setup and execution of a Multidisciplinary Design Analysis and Optimization (MDAO) workflow. The MDAO environment includes the aircraft conceptual design, aircraft performance, structure design, engine design, on-board systems design, RAMS and maintenance cost modules. The RAMS module is used to obtain the failure rates and maintenance effort (in terms of maintenance man hour per flight hour) at subsystem level. The cost module is based on a new maintenance cost model able to estimate the operating cost of the different aircraft variants. The selected new technologies are applied to a regional jet developed within the framework of AGILE research project. For each technology, a different variant of this aircraft is analyzed. Results show that some important saves are reached both in terms of maintenance and fuel cost when new technologies are applied