A Quasi-Experiment Examining Expressive and Receptive Vocabulary Knowledge of Preschool Head Start Children Using Mobile Media Apps

The American Academy of Pediatrics (1999, 2011) recommends no screen time for children under two years and limited screen time for three- and four-year-olds. Despite these recommendations, most young children have easy access to various types of screens. In particular, children*s use of mobile media, including tablets and other touch screen devices, is increasing (Common Sense Media, 2013). Even though scholars have highlighted positive uses for mobile media (Christakis, 2014; Radesky, Schumacher, & Zuckerman, 2015) and there are recommendations in place for using mobile media with young children in active, open-ended ways (NAEYC & Fred Rogers Center, 2012), there has been very limited research conducted on the impact of mobile media on young children*s development. What is more, as early childhood professionals are beginning to incorporate mobile media into their classrooms, they are struggling with the ability to use these devices in developmentally appropriate ways (Marklund, 2015; Nuttall, Edwards, Mantilla, Grieshaber, & Wood, 2015). The primary purpose of the present study was to examine the efficacy of using different types of mobile media apps to increase the receptive and expressive vocabulary development of preschool children living in economically disadvantaged communities. Children and teachers in four Head Start classrooms participated in the quasi-experimental study, which included an eight-week intervention in which the children interacted with one of two types of apps: one classroom used direct instruction vocabulary apps (n = 16) and one classroom used open-ended vocabulary apps (n = 15). Two classrooms served as control groups (n = 18; n = 14) which used apps that were chosen by the Head Start program with no specific instructional method. Children*s vocabulary was assessed pre- and post-intervention. To assess receptive vocabulary, the PPVT-4 (Dunn & Dunn, 2007) and an iPad Receptive Vocabulary Assessment (Vatalaro, 2015a) were used. To assess expressive vocabulary, the EVT-2 (Williams, 2007) and an iPad Expressive Vocabulary Assessment (Vatalaro, 2015b) were used. Using a repeated measures analysis of variance with split plot analysis, children who used direct instruction apps performed statistically significantly higher on the PPVT-4 than children who used open-ended apps. Children in the direct instruction app group also performed statistically significantly higher than both control groups on the iPad Receptive Vocabulary Assessment. There were no statistically significant differences between groups for receptive vocabulary as measured by the EVT-2. However, when children were credited for describing a function instead of the iPad vocabulary word, the analysis of the iPad Expressive Vocabulary Assessment revealed that the children using direct instruction apps performed statistically significantly higher than children using open-ended apps and the children in one of the control groups. A secondary purpose of the present study was to examine the use of apps in mobile media by Head Start teachers. The teachers in the two intervention classrooms participated in weekly meetings with the primary researcher for support in using mobile media in their classrooms in order to ensure that the child intervention was carried out with fidelity. After analyzing data from teachers* self-report daily logs across the eight-week intervention, it was determined that the children received instruction on the assigned apps in both intervention classrooms. Although caution is given to the findings due to some limitations such as the quasi-experimental choice of a research design and the number of participants, the present study contributed to the early childhood research literature with the findings that interactive, animated apps which provide the meanings of vocabulary words in a direct instruction manner may have the ability to increase a child*s receptive vocabulary, and to increase a child*s descriptive definitions of iPad functions. This information increases the chance that teachers in Head Start will begin using direct instruction apps, in the hope of increasing a child*s vocabulary knowledge

A network paradigm for very high capacity mobile and fixed telecommunications ecosystem sustainable evolution

For very high capacity networks (VHC), the main objective is to improve the quality of the end-user experience. This implies compliance with key performance indicators (KPIs) required by applications. Key performance indicators at the application level are throughput, download time, round trip time, and video delay. They depend on the end-to-end connection between the server and the end-user device. For VHC networks, Telco operators must provide the required application quality. Moreover, they must meet the objectives of economic sustainability. Today, Telco operators rarely achieve the above objectives, mainly due to the push to increase the bit-rate of access networks without considering the end-to-end KPIs of the applications. The main contribution of this paper concerns the definition of a deployment framework to address performance and cost issues for VHC networks. We show three actions on which it is necessary to focus. First, limiting bit-rate through video compression. Second, contain the rate of packet loss through artificial intelligence algorithms for line stabilization. Third, reduce latency (i.e., round-trip time) with edge-cloud computing. The concerted and gradual application of these measures can allow a Telco to get out of the ultra-broadband "trap" of the access network, as defined in the paper. We propose to work on end-to-end optimization of the bandwidth utilization ratio. This leads to a better performance experienced by the end-user. It also allows a Telco operator to create new business models and obtain new revenue streams at a sustainable cost. To give a clear example, we describe how to realize mobile virtual and augmented reality, which is one of the most challenging future services.Comment: 42 pages, 4 tables, 6 figures. v2: Revised Englis

An approach to define Very High Capacity Networks with improved quality at an affordable cost

This paper aims to propose one possible approach in the setting of VHCNs (Very High Capacity Networks) performance targets that should be capable of promoting efficient investments for operators and, at the same time, improving the benefits for end-users. To this aim, we suggest relying on some specific KPIs (Key Performance Indicators), especially throughput - i.e., the bandwidth as perceived by the customer - valid at the application layer, instead of the physical layer data-rate. In this regard, the paper underlines that the bandwidth perceived is strictly linked to the latency. The most important implication is that some of the most demanding services envisaged for the future (e.g., mobile virtual and augmented reality, tactile internet) cannot be met by merely increasing the low-level protocol data-rate. Therefore, for the VHCNs reducing latency through Edge Cloud Computing (ECC) is a mandatory pre-requisite.Comment: 6 pages, 4 figures, 1 tabl

Feasibility of an EHF (40/50 GHz) mobile satellite system using highly inclined orbits

The pan-European L-band terrestrial cellular system (GSM) is expected to provide service to more than 10 million users by the year 2000. Discussed here is the feasibility of a new satellite system at EHF (40/50 GHz) to complement, at the end of the decade, the GSM system or its decendants in order to provide additional services at 64 kbits/s, or so. The main system aspects, channel characteristics, technology issues, and both on-board and earth terminal architectures are highlighted. Based on the performed analyses, a proposal was addressed to the Italian Space Agency (ASI), aimed at the implementation of a national plan

La Blockchain e lo sviluppo della moneta di Tezos

La seguente tesi di laurea parla della Blockchain e in particolar modo dello sviluppo della moneta di Tezos. Andremo a vedere le basi che hanno portato alla nascita di questa nuova tecnologia tra cui la storia, l'evoluzione e le caratteristiche; descrivendo alcune delle criptovalute che l'hanno utilizzata tra cui: Bitcoin, Ethereum e, infine Tezos. Affronteremo alcuni paragoni tra le varie criptovalute presentate, in particolar modo il linguaggio di programmazione utilizzato per scrivere gli smart contracts e la sicurezza che ognuna di loro garantisce. Inoltre, parleremo degli smart contracts, di come sono nati e come vengono utilizzati da Ethereum e Tezos

Handover procedures in integrated satellite and terrestrial mobile systems

The integration of satellite and terrestrial mobile systems is investigated in terms of the strategies for handover across the integrated cellular coverage. The handover procedure is subdivided into an initialization phase, where the need for issuing a handover request must be identified, and an execution phase, where the request must be satisfied, if possible, according to a certain channel assignment strategy. A modeling approach that allows the design of the parameters that influence the performance of the overall handover procedure is presented, along with a few numerical results