Vessel segmentation algorithms are the critical components of circulatory blood vessel analysis systems. We present a survey of vessel extraction techniques and algorithms. We put the various vessel extraction approaches and techniques in perspective by means of a classification of the existing research. While we have mainly targeted the extraction of blood vessels, neurosvascular structure in particular, we have also reviewed some of the segmentation methods for the tubular objects that show similar characteristics to vessels. We have divided vessel segmentation algorithms and techniques into six main categories: (1) pattern recognition techniques, (2) model-based approaches, (3) tracking-based approaches, (4) artificial intelligence-based approaches, (5) neural network-based approaches, and (6) tube-like object detection approaches. Some of these categories are further divided into subcategories. We have also created tables to compare the papers in each category against such criteria as dimensionality, input type, preprocessing, user interaction, and result type.

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Gesture and speech combine to form a rich basis for human conversational interaction. To exploit these modalities in HCI, we need to understand the interplay between them and the way in which they support communication. We propose a framework for the gesture research done to date, and present our work on the cross-modal cues for discourse segmentation in free-form gesticulation accompanying speech in natural conversation as a new paradigm for such multimodal interaction. The basis for this integration is the psycholinguistic concept of the coequal generation of gesture and speech from the same semantic intent. We present a detailed case study of a gesture and speech elicitation experiment in which a subject describes her living space to an interlocutor. We perform F. Quek et al.two independent sets of analyses on the video and audio data: video and audio analysis to extract segmentation cues, and expert transcription of the speech and gesture data by microanalyzing the videotape using a frame-accurate videoplayer to correlate the speech with the gestural entities. We compare the results of both analyses to identify the cues accessible in the gestural and audio data that correlate well with the expert psycholinguistic analysis. We show that "handedness" and the kind of symmetry in two-handed gestures provide effective supersegmental discourse cues.

Detection of skin in video is

In this article, we present a new direction for the role of Making for children. Beyond the use of Making to teach specific STEM concepts as is common in prior work, we propose that Making activities should be designed with the focus of instilling a Maker mindset in children. Our target is elementary-school-level children aged 8 to 11. We present an approach that conceptualizes Making as a 'Means-to-an-Ends' to nurture a Maker mindset and identity in children. The approach was embodied in a carefully-designed storytelling Making kit called the Maker Theater, and two Maker workshops for children in the target age range. Our analysis goal in this article was to investigate how the potential for a Maker mindset/identity formation may be manifested in children's attitudes and behaviors. Guided by a theoretical framework of three key determinants of the Maker mindset (self-efficacy, motivation and interest), we analyzed workshop data using qualitative coding methods to derive thematic indicators. We discuss our contributions and the value of our findings for the child-computer interaction community.

In this article, we investigate the child's experience of fun and learning within curriculumintegrated Maker activities in the elementary school classroom. Little is currently understood as to how Making makes learning fun, particularly in formal educational contexts. We conducted an in-the-wild week-long study that implements Maker activities designed with 3 rd , 4 th , and 5 th grade teachers during science classes. Qualitative video-based analysis of the sessions for six students and analysis of all the students' self-reports were performed to derive an understanding of the determinants of fun and learning in the children's experiences. We highlight issues that may inform future directions in the investigation of Making as entertainment technologies in education.

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We present our work on the temporal integration of hierarchies of communicative actions: kinesic, prosodic and discursive. We use the device of the ‘catchment’ as the locus around which this integration proceeds. We present a detailed case study of a gesture and speech elicitation experiment in which a subject describes her living space to an interlocutor. First, we process the video data to obtain the motion traces of both of the subject’s hands using the vector coherence mapping algorithm. We code the gestures to identify the catchments. We recover discourse purposes utilizing a system of guided questions. Finally, we define prosody in terms of the ToBI system. The results of these analyses are compared against the computed motion traces to identify the cues accessible in the gestural and audio data that correlate well with the psycholinguistic analyses. The results show that motion, prosody and discourse structure are integrated at each moment of speaking. The electronic edition of this article includes audio-visual data.