Numerical simulation of flow over a rough bed

This paper presents results of a direct numerical simulation (DNS) of turbulent flow over the rough bed of an open channel. We consider a hexagonal arrangement of spheres on the channel bed. The depth of flow has been taken as four times the diameter of the spheres and the Reynolds number has been chosen so that the roughness Reynolds number is greater than 70, thus ensuring a fully rough flow. A parallel code based on finite difference, domain decomposition, and multigrid methods has been used for the DNS. Computed results are compared with available experimental data. We report the first- and second-order statistics, variation of lift/drag and exchange coefficients. Good agreement with experimental results is seen for the mean velocity, turbulence intensities, and Reynolds stress. Further, the DNS results provide accurate quantitative statistics for rough bed flow. Detailed analysis of the DNS data confirms the streaky nature of the flow near the effective bed and the existence of a hierarchy of vortices aligned with the streamwise direction, and supports the wall similarity hypothesis. The computed exchange coefficients indicate a large degree of mixing between the fluid trapped below the midplane of the roughness elements and that above it

Artefacts as a Cultural and Collaborative Probe in Interaction Design

International audienceThis paper presents a summary analysis of observed case studies within two design network groups. Designers with different backgrounds created some artefacts which permitted to argument that design can be understood as a dialogue approach. The interaction among designers mediated by the artefact allowed to find cultural markers and a collaborative circle especially significant within the design process. A social methodological perspective followed by semioticians was undertaken for the artefacts analysis

Antithetic Conjuncts in Written English

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68390/2/10.1177_003368827901000204.pd

A pragmatic cognitive model for the interpretation of verbal–visual communication in television news programmes

The combination of the verbal and the visual track in television news discourse poses a considerable analytical challenge. In the viewers’ minds the co-habitation of these two semiotic channels triggers a complex network of inferential processes, based on expectations of coherence and relevance, with which they make sense of the representation of the world offered in the news. Through the analysis of a number of news items, this article considers the cognitive processes which viewers may activate when extracting meaning from the multimedial messages contained in television news. The analysis of news items from two British television networks offered by the authors traces the possible meanings that, it is assumed, become available to a potential, ‘idealised’ or ‘implied’ viewer, who accesses the information with some social and cultural knowledge of contemporary Britain. Building on existing studies, the article proposes a model for the classification of verbal–visual relations

Conversational Grammar- Feminine Grammar? A Sociopragmatic Corpus Study

One area in language and gender research that has so far received only little attention is the extent to which the sexes make use of what recent corpus research has termed “conversational grammar.” The author’s initial findings have suggested that the majority of features distinctive of conversational grammar may be used predominantly by female speakers. This article reports on a study designed to test the hypothesis that conversational grammar is “feminine grammar” in the sense that women’s conversational language is more adapted to the conversational situation than men’s. Based on data from the conversational subcorpus of the British National Corpus and following the situational framework for the description of conversational features elaborated in the author’s previous research, features distinctive of conversational grammar are grouped into five functional categories and their normed frequencies compared across the sexes. The functional categories distinguish features that can be seen as adaptations to constraints set by the situational factors of (1) Shared Context, (2) Co-Construction, (3) Real-Time Processing, (4) Discourse Management, and (5) Relation Management. The study’s results, described in detail in relation to the biological category of speaker sex and cultural notions of gender, suggest that the feminine grammar hypothesis is valid

Probabilistic approaches for modeling text structure and their application to text-to-text generation

Since the early days of generation research, it has been acknowledged that modeling the global structure of a document is crucial for producing coherent, readable output. However, traditional knowledge-intensive approaches have been of limited utility in addressing this problem since they cannot be effectively scaled to operate in domain-independent, large-scale applications. Due to this difficulty, existing text-to-text generation systems rarely rely on such structural information when producing an output text. Consequently, texts generated by these methods do not match the quality of those written by humans – they are often fraught with severe coherence violations and disfluencies. In this chapter, I will present probabilistic models of document structure that can be effectively learned from raw document collections. This feature distinguishes these new models from traditional knowledge intensive approaches used in symbolic concept-to-text generation. Our results demonstrate that these probabilistic models can be directly applied to content organization, and suggest that these models can prove useful in an even broader range of text-to-text applications than we have considered here.National Science Foundation (U.S.) (CAREER grant IIS- 0448168)Microsoft Research. New Faculty Fellowshi

Contexting Koreans: Does the High/Low Model Work?

South Korea is assumed to be a high-context culture with extensive shared information and an emphasis on relationships in doing business. The follow ing study reported here tests this assumption and illustrates similarities and differences between Korean and American writers in an attempt to document language differences between high- and low- context societies. Data in the texts studied did not confirm the high/low contextfeatures expected. South Korean texts showed more similarities to than differences from the American texts, and the language features found suggest a more complex context situa tion than the high/low context model may be able to accommodate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66563/2/10.1177_108056999806100403.pd