129 resultados para Vector representation
em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast
Resumo:
Directional Modulation (DM) is a recently proposed technique for securing wireless communication. In this paper we point out that modulation-directionality is a consequence of varying the beamforming network, either in baseband or in the RF stage, at the information rate In order to formalize and extend on previous analysis and synthesis methods a new theoretical treatment using vector representations of directional modulation (DM) systems is introduced and used to obtain the necessary and sufficient con
Resumo:
In most previous research on distributional semantics, Vector Space Models (VSMs) of words are built either from topical information (e.g., documents in which a word is present), or from syntactic/semantic types of words (e.g., dependency parse links of a word in sentences), but not both. In this paper, we explore the utility of combining these two representations to build VSM for the task of semantic composition of adjective-noun phrases. Through extensive experiments on benchmark datasets, we find that even though a type-based VSM is effective for semantic composition, it is often outperformed by a VSM built using a combination of topic- and type-based statistics. We also introduce a new evaluation task wherein we predict the composed vector representation of a phrase from the brain activity of a human subject reading that phrase. We exploit a large syntactically parsed corpus of 16 billion tokens to build our VSMs, with vectors for both phrases and words, and make them publicly available.
Resumo:
Support vector machines (SVMs), though accurate, are not preferred in applications requiring high classification speed or when deployed in systems of limited computational resources, due to the large number of support vectors involved in the model. To overcome this problem we have devised a primal SVM method with the following properties: (1) it solves for the SVM representation without the need to invoke the representer theorem, (2) forward and backward selections are combined to approach the final globally optimal solution, and (3) a criterion is introduced for identification of support vectors leading to a much reduced support vector set. In addition to introducing this method the paper analyzes the complexity of the algorithm and presents test results on three public benchmark problems and a human activity recognition application. These applications demonstrate the effectiveness and efficiency of the proposed algorithm.
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Resumo:
This article discusses women’s political representation in Central and Eastern Europe in the fifteen years after the fall of the Berlin Wall and the adoption of liberal democratic political systems in the region. It highlights the deepseated gender stereotypes that define women primarily as wives and mothers, with electoral politics seen as an appropriate activity for men, but less so for women. The article explores the ways in which conservative attitudes on gender roles hinders the supply of, and demand for, women in the politics of Central and Eastern Europe. It also discusses the manner in which the internalisation of traditional gender norms affects women’s parliamentary behaviour, as few champion women’s rights in the legislatures of the region. The article also finds that links between women MPs and women’s organisations are weak and fragmented, making coalition-building around agendas for women’s rights problematic.
Resumo:
Quantum teleportation for continuous variables is generally described in phase space by using the Wigner functions. We study quantum teleportation via a mixed two-mode squeezed state in Hilbert-Schmidt space by using the coherent-state representation and operators. This shows directly how the teleported state is related to the original state.