3 research outputs found
RRNet: Relational Reasoning Network with Parallel Multi-scale Attention for Salient Object Detection in Optical Remote Sensing Images
Salient object detection (SOD) for optical remote sensing images (RSIs) aims
at locating and extracting visually distinctive objects/regions from the
optical RSIs. Despite some saliency models were proposed to solve the intrinsic
problem of optical RSIs (such as complex background and scale-variant objects),
the accuracy and completeness are still unsatisfactory. To this end, we propose
a relational reasoning network with parallel multi-scale attention for SOD in
optical RSIs in this paper. The relational reasoning module that integrates the
spatial and the channel dimensions is designed to infer the semantic
relationship by utilizing high-level encoder features, thereby promoting the
generation of more complete detection results. The parallel multi-scale
attention module is proposed to effectively restore the detail information and
address the scale variation of salient objects by using the low-level features
refined by multi-scale attention. Extensive experiments on two datasets
demonstrate that our proposed RRNet outperforms the existing state-of-the-art
SOD competitors both qualitatively and quantitatively.Comment: 11 pages, 9 figures, Accepted by IEEE Transactions on Geoscience and
Remote Sensing 2021, project: https://rmcong.github.io/proj_RRNet.htm
Do We Fully Understand Students' Knowledge States? Identifying and Mitigating Answer Bias in Knowledge Tracing
Knowledge tracing (KT) aims to monitor students' evolving knowledge states
through their learning interactions with concept-related questions, and can be
indirectly evaluated by predicting how students will perform on future
questions. In this paper, we observe that there is a common phenomenon of
answer bias, i.e., a highly unbalanced distribution of correct and incorrect
answers for each question. Existing models tend to memorize the answer bias as
a shortcut for achieving high prediction performance in KT, thereby failing to
fully understand students' knowledge states. To address this issue, we approach
the KT task from a causality perspective. A causal graph of KT is first
established, from which we identify that the impact of answer bias lies in the
direct causal effect of questions on students' responses. A novel
COunterfactual REasoning (CORE) framework for KT is further proposed, which
separately captures the total causal effect and direct causal effect during
training, and mitigates answer bias by subtracting the latter from the former
in testing. The CORE framework is applicable to various existing KT models, and
we implement it based on the prevailing DKT, DKVMN, and AKT models,
respectively. Extensive experiments on three benchmark datasets demonstrate the
effectiveness of CORE in making the debiased inference for KT.Comment: 13 page