6,456 research outputs found

    Real-time activity recognition by discerning qualitative relationships between randomly chosen visual features

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    In this paper, we present a novel method to explore semantically meaningful visual information and identify the discriminative spatiotemporal relationships between them for real-time activity recognition. Our approach infers human activities using continuous egocentric (first-person-view) videos of object manipulations in an industrial setup. In order to achieve this goal, we propose a random forest that unifies randomization, discriminative relationships mining and a Markov temporal structure. Discriminative relationships mining helps us to model relations that distinguish different activities, while randomization allows us to handle the large feature space and prevents over-fitting. The Markov temporal structure provides temporally consistent decisions during testing. The proposed random forest uses a discriminative Markov decision tree, where every nonterminal node is a discriminative classifier and the Markov structure is applied at leaf nodes. The proposed approach outperforms the state-of-the-art methods on a new challenging video dataset of assembling a pump system

    Coarse Temporal Attention Network (CTA-Net) for Driver’s Activity Recognition

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    There is significant progress in recognizing traditional human activities from videos focusing on highly distinctive actions involving discriminative body movements, body-object and/or human-human interactions. Driver's activities are different since they are executed by the same subject with similar body parts movements, resulting in subtle changes. To address this, we propose a novel framework by exploiting the spatiotemporal attention to model the subtle changes. Our model is named Coarse Temporal Attention Network (CTA-Net), in which coarse temporal branches are introduced in a trainable glimpse network. The goal is to allow the glimpse to capture high-level temporal relationships, such as 'during', 'before' and 'after' by focusing on a specific part of a video. These branches also respect the topology of the temporal dynamics in the video, ensuring that different branches learn meaningful spatial and temporal changes. The model then uses an innovative attention mechanism to generate high-level action specific contextual information for activity recognition by exploring the hidden states of an LSTM. The attention mechanism helps in learning to decide the importance of each hidden state for the recognition task by weighing them when constructing the representation of the video. Our approach is evaluated on four publicly accessible datasets and significantly outperforms the state-of-the-art by a considerable margin with only RGB video as input.Comment: Extended version of the accepted WACV 202

    Trying to break new ground in aerial archaeology

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    Aerial reconnaissance continues to be a vital tool for landscape-oriented archaeological research. Although a variety of remote sensing platforms operate within the earth’s atmosphere, the majority of aerial archaeological information is still derived from oblique photographs collected during observer-directed reconnaissance flights, a prospection approach which has dominated archaeological aerial survey for the past century. The resulting highly biased imagery is generally catalogued in sub-optimal (spatial) databases, if at all, after which a small selection of images is orthorectified and interpreted. For decades, this has been the standard approach. Although many innovations, including digital cameras, inertial units, photogrammetry and computer vision algorithms, geographic(al) information systems and computing power have emerged, their potential has not yet been fully exploited in order to re-invent and highly optimise this crucial branch of landscape archaeology. The authors argue that a fundamental change is needed to transform the way aerial archaeologists approach data acquisition and image processing. By addressing the very core concepts of geographically biased aerial archaeological photographs and proposing new imaging technologies, data handling methods and processing procedures, this paper gives a personal opinion on how the methodological components of aerial archaeology, and specifically aerial archaeological photography, should evolve during the next decade if developing a more reliable record of our past is to be our central aim. In this paper, a possible practical solution is illustrated by outlining a turnkey aerial prospection system for total coverage survey together with a semi-automated back-end pipeline that takes care of photograph correction and image enhancement as well as the management and interpretative mapping of the resulting data products. In this way, the proposed system addresses one of many bias issues in archaeological research: the bias we impart to the visual record as a result of selective coverage. While the total coverage approach outlined here may not altogether eliminate survey bias, it can vastly increase the amount of useful information captured during a single reconnaissance flight while mitigating the discriminating effects of observer-based, on-the-fly target selection. Furthermore, the information contained in this paper should make it clear that with current technology it is feasible to do so. This can radically alter the basis for aerial prospection and move landscape archaeology forward, beyond the inherently biased patterns that are currently created by airborne archaeological prospection

    An EEG-based neural decoding approach for investigating statistical learning between modalities

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    We researched cross-modal statistical learning conducting to experiments: a behavioural one and a neuroimaging one. In the analysis of the later we used neural decoding with temporal generalization

    On the determination of human affordances

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    Communicating Multiplicative Reasoning Through Semiotic Resources

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    The importance of fostering in students the requisite language to understand what is being communicated and how to communicate their understanding requires educators to conceptualize themselves as teachers of language and content. It is possible to engage in activities of the mathematics classroom and through that participation engage in language practices and mathematical practices simultaneously. The purpose of this study was to explore the use of semiotic resources, and modality, with a student-generated tool on students’ communication of multiplicative reasoning. The study design was a qualitative case study that included a single third-grade class with an in-depth look at six students of varying knowledge levels. Two students, one male and one female, were randomly selected from Beyond, On, and Approaching levels. Discourse analysis served dual purposes for the data collected: first, it explored a socially constructed multi-modal tool utilized as an activity to enhance language use individually and interactively during mathematical discourse; second, it supported investigating the language used by participants during the studied activities and how they relate to Communication About and Communication In multiplication. The findings support the utilization of semiotic resources, inclusive of visual representations, signs, symbolic notations, and receptive and expressive language elements as fundamental to the learning and communication we are asking of our students. Through the interplay of semiotic resources, a multimodal student-generated tool can support students in summarizing their learning, individually and interactively, enhancing their means of communicating discursively in mathematics

    The Effect of Gender on Spatial Ability and Spatial Reasoning Among Students in Grades 2-8

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    The purpose of this study was to examine gender differences across three types of spatial ability; namely, spatial perception, spatial visualization, and mental rotation in conjunction with working memory. The study utilized a causal-comparative research design involving group comparisons. In this design researchers collect data about variables that they have conceptualized to be in a causal relationship to each other, but there is no intervention as in experimental research. Participants in this study included approximately 200 students in second through eighth grades at one public school and one public charter school, all located in the same school district/county. Spatial ability was measured by four categories of spatial relations tests based upon spatial cognition research proposing that spatial cognition is comprised of “three separable dimensions:” the Mental Folding Test for Children (spatial visualization), an adaptation of the Differential Aptitude Test: Space Relations (DAT: SR), Mental Rotation for Children, an adaptation of the Mental Rotations Test (MRT), Manikin Test (spatial orientation and transformation), and Mr. Peanut Test (visuo-spatial working memory). The resultant scores were used as measures of mathematical achievement and cognitive ability. Data were analyzed using MANOVA and ANOVA statistical analysis. Results suggested that mostly non-significant differences exist for spatial visualization abilities between males and females. The sole example of a significant difference between male and females was noted on the Mr. Peanut test in the fourth and fifth grades, accompanied with a partial Eta Squared (ղ2) of .10
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