730 research outputs found

    Future Open Mobile Services

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    The major barriers for the success of mobile data services are the lack of comprehensible mobile service architectures, their confusing business models and the complexity combined with the inconsistency of the technology enablers. This paper attempts to present a more structured and comprehensive analysis of the current mobile service architectures and their technology enablers. The paper starts with a thorough study of the evolution of mobile services and their business models, and a collection of expectations of the different actors, including the end-user. Next, starting from the original mobile services architecture and environment, an attempt to place the different technology enablers in relation to each other and in relation to their position in the mobile system, will be carried out. Each technology enabler together with their contribution in the enhancement of mobile services are then summarised in a complete and comprehensive way. The paper concludes with a recapitulation of the achievement of the state-of-the-art technology enablers and an identification of future improvements

    Strong Authentication for Web services with Mobile Universal Identity

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    To access services on the Web, users need quite often to have accounts, i.e. user names and passwords. This becomes a problem when the number of accounts keeps increasing at the same time password is a very weak form of authentication exposing the users to fraud and abuses. To address both mentioned issues we propose a Mobile Universal identity, which by combining Internet identifiers with mobile identifiers is capable of delivering strong authentication for Internet services. By introducing an identity provider, the solution enables the user to employ the Mobile Universal identity for multiple service providers. By federation with other identities, Mobile Universal identity can be used with service providers worldwide.© Springer International Publishing Switzerland 2015. This is the authors' accepted and refereed manuscript to the article. Locked until 2016-08-08

    Influence of temperature on mechanical characteristics of 1018 low carbon steel estimated by ultrasonic non-destructive testing method

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    The temperature dependence of ultrasonic velocities propagated in low carbon steel 1018 has been investigated by the A-scan mode of the ultrasonic non-destructive testing method. Experimental results show that these velocities are linearly dependent on temperature of the carbon steel sample in the range of 0 to 50 °C. Based on the experimental velocities of the longitudinal wave and the shear one, mechanical characteristics of this carbon steel including Poisson's ratio (υ), Young’s modulus (E), shear modulus (G), and bulk modulus (K) have been calculated. These mechanical characteristics have also been linear response with respect to the increase of sample’s temperature. By using linear fitting approach, the temperature dependence coefficients of these mechanical characteristics have been analyzed and estimated to be 9.76×10-6/°C, −0.057 GPa/°C, −0.023 GPa/°C, and −0.038 GPa/°C for v, E, G, and K, respectively. It is concluded that the influence of the temperature on the mechanical properties of the carbon steels is necessary determined due to the improved accuracy of the ultrasonic testing method

    Enabling non-linear energy harvesting in power domain based multiple access in relaying networks: Outage and ergodic capacity performance analysis

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    The Power Domain-based Multiple Access (PDMA) scheme is considered as one kind of Non-Orthogonal Multiple Access (NOMA) in green communications and can support energy-limited devices by employing wireless power transfer. Such a technique is known as a lifetime-expanding solution for operations in future access policy, especially in the deployment of power-constrained relays for a three-node dual-hop system. In particular, PDMA and energy harvesting are considered as two communication concepts, which are jointly investigated in this paper. However, the dual-hop relaying network system is a popular model assuming an ideal linear energy harvesting circuit, as in recent works, while the practical system situation motivates us to concentrate on another protocol, namely non-linear energy harvesting. As important results, a closed-form formula of outage probability and ergodic capacity is studied under a practical non-linear energy harvesting model. To explore the optimal system performance in terms of outage probability and ergodic capacity, several main parameters including the energy harvesting coefficients, position allocation of each node, power allocation factors, and transmit signal-to-noise ratio (SNR) are jointly considered. To provide insights into the performance, the approximate expressions for the ergodic capacity are given. By matching analytical and Monte Carlo simulations, the correctness of this framework can be examined. With the observation of the simulation results, the figures also show that the performance of energy harvesting-aware PDMA systems under the proposed model can satisfy the requirements in real PDMA applications.Web of Science87art. no. 81

    Uma pesquisa-ação de 3 anos em uma universidade vietnamita: Alunos como cogeradores de conteúdo das aulas

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    In the context of the 4th Industrial Revolution with unlimited technological advancement and innovation, how can educators innovate their teaching and facilitate their students in their learning process, so that students can accumulate required skills and achieve the set learning outcomes of each course they take? In order to find out the answer, the authors have revised some literature concerning BYOD trend, active learning strategies, flipped classroom and learner-generated content as the theoretical base for their study. Action research has been conducted at a Vietnamese university with the participation of English-majored students in Theory of English Translation and Interpreting classes from 3 different intakes. The findings include students’ positive perception towards the content-generation practices. Some achievements and challenges in the teaching and learning process have also been reported. This paper also recommends further studies so that the practice could be utilized to the best outcomes.En el contexto de la Cuarta Revolución Industrial con un avance tecnológico e innovación ilimitados, ¿cómo pueden los educadores innovar su enseñanza y facilitar a sus estudiantes su proceso de aprendizaje, para que los estudiantes puedan acumular las habilidades requeridas y lograr los resultados de aprendizaje establecidos en cada curso que toman? Para encontrar la respuesta, los autores han revisado cierta literatura sobre la tendencia BYOD, las estrategias de aprendizaje activo, el aula invertida y el contenido generado por el alumno como base teórica para su estudio. Se llevó a cabo una investigación de acción en una universidad vietnamita con la participación de estudiantes con especialización en inglés en clases de Teoría de la traducción e interpretación en inglés de 3 tomas diferentes. Los hallazgos incluyen la percepción positiva de los estudiantes hacia las prácticas de generación de contenidos. También se reportan algunos logros y desafíos en el proceso de enseñanza y aprendizaje. Este documento también recomienda más estudios para que la práctica pueda utilizarse con los mejores resultados.No contexto da 4ª Revolução Industrial, com avanço tecnológico e inovação ilimitados, como os educadores podem inovar seu ensino e facilitar seus alunos em seu processo de aprendizagem, para que os alunos possam acumular as habilidades necessárias e alcançar os resultados de aprendizagem definidos de cada curso que fazem? Para encontrar a resposta, os autores revisaram alguma literatura sobre a tendência BYOD, estratégias de aprendizagem ativa, sala de aula invertida e conteúdo gerado pelo aluno como base teórica para seu estudo. Uma pesquisa-ação foi realizada em uma universidade vietnamita com a participação de alunos formados em inglês nas aulas de Teoria da Tradução e Interpretação do Inglês de 3 diferentes entradas. Os resultados incluem a percepção positiva dos alunos em relação às práticas de geração de conteúdo. Algumas conquistas e desafios no processo de ensino e aprendizagem também foram relatados. Este artigo também recomenda mais estudos para que a prática possa ser utilizada para os melhores resultados

    Joint Fixed Power Allocation and Partial Relay Selection Schemes for Cooperative NOMA

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     In the future wireless systems, non-orthogonal multiple-access (NOMA) with partial relay selection scheme is considered as developing research topic. In this paper, dual-hop relaying systems is deployed for NOMA, in which the signal is transfered with the assistance of decode-and-forward (DF) scheme. This paper presents exact expressions for outage probability over independent Rayleigh fading channels, and two partial relay selection schemes are provided. Using matching analytical result and Monte-Carlo method, we introduce forwarding strategy selection for fixed user allocation and exactness of derived formula is checked. The presented simulations confirm the the advantage of such considered NOMA, and the effectiveness of the proposed forwarding strategy

    Stability of the principles of minimal specificity and maximal buoyancy

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    The aim of  this paper is to investigate an use of  the principles of minimal Specificity and maximal Buoyancy (MB) proposed by R.R.Yager and to introduced some conditions of a set of possibility distributions and  weights which guarantee uniqueness of  possibility distribution selected by the use of these principles from a given set of  distributions

    Professional development for ESL lecturers – a struggle to integrate ICT into teaching

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    Information and Communications Technology (ICT) plays a crucial role in our daily life. In fact, students are considered digital citizens and have become accustomed to being always connected to their devices and the Internet. Given the importance ICT plays in our lives, education institutions nowadays have a duty to incorporate ICT into teaching and learning in order to better prepare students for 21st Century skills and careers. Although certain technological equipment may be available in classrooms, there are several external and internal factors that affect the proper implementation of ICT in classrooms. In preparing students to be career-ready, ICT integration is imperative. This paper will discuss factors affecting ESL lecturers’ professional development in terms of ICT application in the classroom. A total of 61 lecturers from 12 non-English-majored universities in Vietnam voluntarily completed this quantitative study’s survey questionnaire. The findings show that although ESL lecturers are aware of the significance of some factors affecting ICT implementation in classrooms, they are struggling to learn, to adapt, and to integrate ICT into their classrooms
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