Multimodal Definition: The Multiplication of Meaning in Electronic Dictionaries

With the popularity of electronic dictionaries, multimodality plays an increasingly important role in lexicography. To broaden the horizons of e-dictionary definitions, this article argues for the establishment of a new term, multimodal definition, as a key component of multimodal lexicography. This term integrates verbal definitions and the complementary multimodal resources from a holistic viewpoint of meaning. In a multimodal definition, a dynamic meaning ecology can be formed, with two critical variables functioning, (semiotic) mode selection and intermodal synergy. In this ecology, meaning expressed verbally can be multiplied in four dimensions: content, form, space and time. Future directions for research are discussed, including dictionary user studies and multimodal corpora. The findings of this article shed light on the construction of a theoretical model for e-lexicography which remains an urgent task in the ongoing digital revolution.Keywords: Multimodality, multimodal definition, multimodal lexicography, e-dictionary, mode selection, intermodal synergy

Multimodal exemplification: The expansion of meaning in electronic dictionaries

This article investigates electronic dictionaries under the framework of Systemic-Functional Multimodal Discourse Analysis (SF-MDA) and argues for improving their exemplifica-tion multimodally. Multimodal devices, if well coordinated, can help optimize e-dictionary exam-ples in informativity, diversity, dynamicity and  interactivity. The term multimodal exemplification is tentatively proposed under the umbrella of multimodal lexicography (Lew 2010), and defined as the selection and presentation of examples with multimodal devices for achieving greater effec-tiveness in exemplifying than language does alone, especially in an e-dictionary. Evidence shows that multimodal exemplification can expand the three  metafunctional meanings of the e-dictionary discourse: ideational, interpersonal and textual. Ideational meaning can be enriched by not only multimodal examples per se but also cross-modal example–definition ties, and hyperlinks facilitate meaning flow in the semantic network. Interpersonal meaning can be expanded by user  participa-tion and design options, including those for page layout (spatial mode) and example genre style (verbal mode). Textual meaning can be reinforced by  information value, composition, salience and framing. This article makes a first  attempt to explore the intermodal relationship between a defini-tion and the  examples under the same sense, and to present a diagram illustrating a typical design of visual space in e-dictionaries. By exploring the special features of multimodal example texts, it may deepen our understanding of the emerging multimodal lexicography and complement multi-modal discourse studies from a lexicographical perspective. Keywords: E-Dictionary, Example, Metafunctional Meaning, Multimodal Discourse Analysis, Multimodal Exemplification, Multimodal Lexicog-Raph

Radar Waveform Design for Extended Target Recognition under Detection Constraints

We address the problem of radar phase-coded waveform design for extended target recognition in the presence of colored Gaussian disturbance. Phase-coded waveforms are selected since they can fully exploit the transmit power with sufficient variability. An important constraint, target detection performance, is considered to meet the practical requirements. The waveform is designed to achieve maximum recognition performance under a control on the achievable signal-to-noise ratio (SNR) of every possible target hypothesis. We formulate the code design in terms of a nonconvex, NP-hard quadratic optimization problem in the cases of both continuous and discrete phases. Techniques based on semidefinite relaxation (SDR) and randomization are proposed to approximate the optimal solutions. Simulation results show that the recognition performance and the detection requirements are well balanced and accurate approximations are achieved