1,732 research outputs found

    On explicit relations between cyclotomic numbers

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    About the kernel of the augmentation of finitely generated Z-modules

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    Let M be a free finitely generated Z-module with basis B and ΔM the kernel of the homomorphism M→Z which maps B to 1. A basis of ΔM can be easily constructed from the basis B of M. Let further R be a submodule of M such that N = M/R is free. The subject of investigation is the module ΔN = (ΔM + R) / R. We compute the index [N:ΔN] and construct bases of ΔN with the help of a basis of N. Finally, the results are applied to a special class of modules which is connected with the group of cyclotomic units

    A gentle transition from Java programming to Web Services using XML-RPC

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    Exposing students to leading edge vocational areas of relevance such as Web Services can be difficult. We show a lightweight approach by embedding a key component of Web Services within a Level 3 BSc module in Distributed Computing. We present a ready to use collection of lecture slides and student activities based on XML-RPC. In addition we show that this material addresses the central topics in the context of web services as identified by Draganova (2003)

    Supervised ANN vs. unsupervised SOM to classify EEG data for BCI: why can GMDH do better?

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    Construction of a system for measuring the brain activity (electroencephalogram (EEG)) and recognising thinking patterns comprises significant challenges, in addition to the noise and distortion present in any measuring technique. One of the most major applications of measuring and understanding EGG is the brain-computer interface (BCI) technology. In this paper, ANNs (feedforward back -prop and Self Organising Maps) for EEG data classification will be implemented and compared to abductive-based networks, namely GMDH (Group Methods of Data Handling) to show how GMDH can optimally (i.e. noise and accuracy) classify a given set of BCI’s EEG signals. It is shown that GMDH provides such improvements. In this endeavour, EGG classification based on GMDH will be researched for comprehensible classification without scarifying accuracy. GMDH is suggested to be used to optimally classify a given set of BCI’s EEG signals. The other areas related to BCI will also be addressed yet within the context of this purpose

    Nontrivial Galois module structure of cyclotomic fields

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    We say a tame Galois field extension L/KL/K with Galois group GG has trivial Galois module structure if the rings of integers have the property that \Cal{O}_{L} is a free \Cal{O}_{K}[G]-module. The work of Greither, Replogle, Rubin, and Srivastav shows that for each algebraic number field other than the rational numbers there will exist infinitely many primes ll so that for each there is a tame Galois field extension of degree ll so that L/KL/K has nontrivial Galois module structure. However, the proof does not directly yield specific primes ll for a given algebraic number field K.K. For KK any cyclotomic field we find an explicit ll so that there is a tame degree ll extension L/KL/K with nontrivial Galois module structure

    Object shadowing – a key concept for a modern programming language

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    Objects, worlds, and students: virtual interaction in education

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    The main aim of this study is to form a complete taxonomy of the types of interactions that relate to the use of a virtual world for engaging learning experiences, when blended and hybrid learning methods are to be used. In order to investigate this topic more accurately and effectively, we distinguish four dimensions of interactions based on the context in which these occur, and the involved parts: in-world and in-class, user-to-user and user-to-world interactions. In order to conduct investigation into this topic and form a view of the interactions as clear as possible, we observed a cohort of 15 undergraduate Computer Science students while using an OpenSim-based institutionally hosted virtual world. Moreover, we ran a survey where 50 students were asked to indicate their opinion and feelings about their in-world experience. The results of our study highlight that educators and instructors need to plan their in-world learning activities very carefully and with a focus on interactions if engaging activities are what they want to offer their students. Additionally, it seems that student interactions with the content of the virtual world and the in-class student-to-student interactions, have stronger impact on students’ engagement when hybrid methods are used

    Responsibility and non-repudiation in resource-constrained Internet of Things scenarios

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    The proliferation and popularity of smart autonomous systems necessitates the development of methods and models for ensuring the effective identification of their owners and controllers. The aim of this paper is to critically discuss the responsibility of Things and their impact on human affairs. This starts with an in-depth analysis of IoT Characteristics such as Autonomy, Ubiquity and Pervasiveness. We argue that Things governed by a controller should have an identifiable relationship between the two parties and that authentication and non-repudiation are essential characteristics in all IoT scenarios which require trustworthy communications. However, resources can be a problem, for instance, many Things are designed to perform in low-powered hardware. Hence, we also propose a protocol to demonstrate how we can achieve the authenticity of participating Things in a connectionless and resource-constrained environment
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