27 research outputs found

    Communication error detection using facial expressions

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 129-135).Automatic detection of communication errors in conversational systems typically rely only on acoustic cues. However, perceptual studies have indicated that speakers do exhibit visual communication error cues passively during the system's conversational turn. In this thesis, we introduce novel algorithms for face and body gesture recognition and present the first automatic system for detecting communication errors using facial expressions during the system's turn. This is useful as it detects communication problems before the user speaks a reply. To detect communication problems accurately and efficiently we develop novel extensions to hidden-state discriminative methods. We also present results that show when human subjects become aware that the conversational system is capable of receiving visual input, they become more communicative visually yet naturally.by Sy Bor Wang.Ph.D

    Sex Determination in the Squalius alburnoides Complex: An Initial Characterization of Sex Cascade Elements in the Context of a Hybrid Polyploid Genome

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    BACKGROUND:Sex determination processes vary widely among different vertebrate taxa, but no group offers as much diversity for the study of the evolution of sex determination as teleost fish. However, the knowledge about sex determination gene cascades is scarce in this species-rich group and further difficulties arise when considering hybrid fish taxa, in which mechanisms exhibited by parental species are often disrupted. Even though hybridisation is frequent among teleosts, gene based approaches on sex determination have seldom been conducted in hybrid fish. The hybrid polyploid complex of Squalius alburnoides was used as a model to address this question. METHODOLOGY/PRINCIPAL FINDINGS:We have initiated the isolation and characterization of regulatory elements (dmrt1, wt1, dax1 and figla) potentially involved in sex determination in S. alburnoides and in the parental species S. pyrenaicus and analysed their expression patterns by in situ hybridisation. In adults, an overall conservation in the cellular localization of the gene transcripts was observed between the hybrids and parental species. Some novel features emerged, such as dmrt1 expression in adult ovaries, and the non-dimorphic expression of figla, an ovarian marker in other species, in gonads of both sexes in S. alburnoides and S. pyrenaicus. The potential contribution of each gene to the sex determination process was assessed based on the timing and location of expression. Dmrt1 and wt1 transcripts were found at early stages of male development in S. alburnoides and are most likely implicated in the process of gonad development. CONCLUSIONS/SIGNIFICANCE:For the first time in the study of this hybrid complex, it was possible to directly compare the gene expression patterns between the bisexual parental species and the various hybrid forms, for an extended set of genes. The contribution of these genes to gonad integrity maintenance and functionality is apparently unaltered in the hybrids, suggesting that no abrupt shifts in gene expression occurred as a result of hybridisation

    A multimodal galaxy-based geographic system

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    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.Includes bibliographical references (p. 63-64).by Sy Bor Wang.S.M

    The SQL-AG System

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    Detecting communication errors from visual cues durin

    Hidden Conditional Random Fields for Gesture Recognition

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    We introduce a discriminative hidden-state approach for the recognition of human gestures. Gesture sequences often have a complex underlying structure, and models that can incorporate hidden structures have proven to be advantageous for recognition tasks. Most existing approaches to gesture recognition with hidden states employ a Hidden Markov Model or suitable variant (e.g., a factored or coupled state model) to model gesture streams; a significant limitation of these models is the requirement of conditional independence of observations. In addition, hidden states in a generative model are selected to maximize the likelihood of generating all the examples of a given gesture class, which is not necessarily optimal for discriminating the gesture class against other gestures. Previous discriminative approaches to gesture sequence recognition have shown promising results, but have not incorporated hidden states nor addressed the problem of predicting the label of an entire sequence. In this paper, we derive a discriminative sequence model with a hidden state structure, and demonstrate its utility both in a detection and in a multi-way classification formulation. We evaluate our method on the task of recognizing human arm and head gestures, and compare the performance of our method to both generative hidden state and discriminative fully-observable models. 1

    Networked Intelligent Collaborative Environment (NetICE

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    This paper presents NetICE, Networked Intelligent Collaborative Environment, which is a prototype designated to provide an immersive environment to allow people to communicate from anywhere at any time. The NetICE system consists of two components: an intelligent network and smart terminals. The intelligent network allows multiple users to be connected to the same virtual space. The smart terminals provide an immersive environment to the end users by using audio-visual communication and 3D computer graphics animation techniques. 1

    The Bottlenecks of Preparing Virus Particles by Size Exclusion for Antibody Generation

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    Enterovirus 71 (EV71) is the major etiological agent contributing to the development of hand-foot-mouth disease (HFMD). There are not any global available vaccines or antibody drugs against EV71 released yet. In this study, we perform the virus immunization in a cost-effective and convenient approach by preparing virus particles from size exclusion and immunization of chicken. Polyclonal yolk-immunoglobulin (IgY) was simply purified from egg yolk and monoclonal single-chain variable fragments (scFv) were selected via phage display technology with two scFv libraries containing 6.0 × 106 and 1.3 × 107 transformants. Specific clones were enriched after 5 rounds of bio-panning and four identical genes were classified after the sequence analysis. Moreover, the higher mutation rates were revealed in the CDR regions, especially in the CDR3. IgY showed specific binding activities to both EV71-infected and Coxsackievirus 16-infected cell lysates and high infectivity inhibitory activity of EV71. However, while IgY detected a 37 kDa protein, the selected scFv seemingly detected higher size proteins which could be cell protein instead of EV71 proteins. Despite the highly effective chicken antibody generation, the purity of virus particles prepared by size exclusion is the limitation of this study, and further characterization should be carried out rigorously
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