90 research outputs found

    An Examination of the Effect of Multiple Supervisors on Flight Trainees\u27 Performance

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    One of the major roles of the flight supervisory control during flight training is that a trainee is guided to stay within acceptable range of flight performance parameters. Under the supervisory control during flight training, however, a trainee may perceive psychological stress. Literature suggests that when pilots are monitored by flight supervisor during flight training, their perception of psychological stress may increase and thus, result in increasing flight performance. This work proposes to examine whether the presence of flight supervisors has an effect on trainee’s performance. This study will further find the number of flight supervisors needed for pilot flight training. An empirical result of the present research study is expected to provide practical implications as to how differently trainees will perform under the supervision of single supervisor versus multiple supervisors. The present work will statistically verify one research hypotheses. The hypothesis is that flight trainee’s performance would increase under the condition of multiple supervisors compared with single supervisor. Independent variables include the presence of supervisor (1 vs. 3) and scenario order presented with participants. Dependent variables include three types of flight performance (performance on skill, scanning, and task load). A within-subject two-way ANOVA with counterbalancing mixed design will be conducted to statistically verify the research hypothesis. A sample size of this research study is 32 participants

    Effective Discriminative Feature Selection with Non-trivial Solutions

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    Feature selection and feature transformation, the two main ways to reduce dimensionality, are often presented separately. In this paper, a feature selection method is proposed by combining the popular transformation based dimensionality reduction method Linear Discriminant Analysis (LDA) and sparsity regularization. We impose row sparsity on the transformation matrix of LDA through ℓ2,1{\ell}_{2,1}-norm regularization to achieve feature selection, and the resultant formulation optimizes for selecting the most discriminative features and removing the redundant ones simultaneously. The formulation is extended to the ℓ2,p{\ell}_{2,p}-norm regularized case: which is more likely to offer better sparsity when 0<p<10<p<1. Thus the formulation is a better approximation to the feature selection problem. An efficient algorithm is developed to solve the ℓ2,p{\ell}_{2,p}-norm based optimization problem and it is proved that the algorithm converges when 0<p≤20<p\le 2. Systematical experiments are conducted to understand the work of the proposed method. Promising experimental results on various types of real-world data sets demonstrate the effectiveness of our algorithm

    Profile-based Maximum Penalised Likelihood Trajectory Estimation from Space-borne LOS Measurements

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    Estimating the boost-phase trajectory of a ballistic missile using line of sight measurements from space-borne passive sensors is an important issue in missile defense. A well-known difficulty of this issue is the poor-observability of the target motion. A profile-based maximum penalised likelihood estimator is presented, which is expected to work in poor-observability scenarios. Firstly, a more adaptable boost-phase profile is proposed by introducing unknown parameters. Then, the estimator is given based on the Bayesian paradigm. After that, a special penalty for box constraint is constructed based on a mixed distribution. Numerical results for some typical scenarios and sensitivity with respect to a priori information are reported to show that the proposed estimator is promising

    SCA-PVNet: Self-and-Cross Attention Based Aggregation of Point Cloud and Multi-View for 3D Object Retrieval

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    To address 3D object retrieval, substantial efforts have been made to generate highly discriminative descriptors of 3D objects represented by a single modality, e.g., voxels, point clouds or multi-view images. It is promising to leverage the complementary information from multi-modality representations of 3D objects to further improve retrieval performance. However, multi-modality 3D object retrieval is rarely developed and analyzed on large-scale datasets. In this paper, we propose self-and-cross attention based aggregation of point cloud and multi-view images (SCA-PVNet) for 3D object retrieval. With deep features extracted from point clouds and multi-view images, we design two types of feature aggregation modules, namely the In-Modality Aggregation Module (IMAM) and the Cross-Modality Aggregation Module (CMAM), for effective feature fusion. IMAM leverages a self-attention mechanism to aggregate multi-view features while CMAM exploits a cross-attention mechanism to interact point cloud features with multi-view features. The final descriptor of a 3D object for object retrieval can be obtained via concatenating the aggregated features from both modules. Extensive experiments and analysis are conducted on three datasets, ranging from small to large scale, to show the superiority of the proposed SCA-PVNet over the state-of-the-art methods

    Keyword-Aware Relative Spatio-Temporal Graph Networks for Video Question Answering

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    The main challenge in video question answering (VideoQA) is to capture and understand the complex spatial and temporal relations between objects based on given questions. Existing graph-based methods for VideoQA usually ignore keywords in questions and employ a simple graph to aggregate features without considering relative relations between objects, which may lead to inferior performance. In this paper, we propose a Keyword-aware Relative Spatio-Temporal (KRST) graph network for VideoQA. First, to make question features aware of keywords, we employ an attention mechanism to assign high weights to keywords during question encoding. The keyword-aware question features are then used to guide video graph construction. Second, because relations are relative, we integrate the relative relation modeling to better capture the spatio-temporal dynamics among object nodes. Moreover, we disentangle the spatio-temporal reasoning into an object-level spatial graph and a frame-level temporal graph, which reduces the impact of spatial and temporal relation reasoning on each other. Extensive experiments on the TGIF-QA, MSVD-QA and MSRVTT-QA datasets demonstrate the superiority of our KRST over multiple state-of-the-art methods.Comment: under revie

    A Study on Differentiable Logic and LLMs for EPIC-KITCHENS-100 Unsupervised Domain Adaptation Challenge for Action Recognition 2023

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    In this technical report, we present our findings from a study conducted on the EPIC-KITCHENS-100 Unsupervised Domain Adaptation task for Action Recognition. Our research focuses on the innovative application of a differentiable logic loss in the training to leverage the co-occurrence relations between verb and noun, as well as the pre-trained Large Language Models (LLMs) to generate the logic rules for the adaptation to unseen action labels. Specifically, the model's predictions are treated as the truth assignment of a co-occurrence logic formula to compute the logic loss, which measures the consistency between the predictions and the logic constraints. By using the verb-noun co-occurrence matrix generated from the dataset, we observe a moderate improvement in model performance compared to our baseline framework. To further enhance the model's adaptability to novel action labels, we experiment with rules generated using GPT-3.5, which leads to a slight decrease in performance. These findings shed light on the potential and challenges of incorporating differentiable logic and LLMs for knowledge extraction in unsupervised domain adaptation for action recognition. Our final submission (entitled `NS-LLM') achieved the first place in terms of top-1 action recognition accuracy.Comment: Technical report submitted to CVPR 2023 EPIC-Kitchens challenge
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