2,618 research outputs found
On the "Security analysis and improvements of arbitrated quantum signature schemes"
Recently, Zou et al. [Phys. Rev. A 82, 042325 (2010)] pointed out that two
arbitrated quantum signature (AQS) schemes are not secure, because an
arbitrator cannot arbitrate the dispute between two users when a receiver
repudiates the integrity of a signature. By using a public board, they try to
propose two AQS schemes to solve the problem. This work shows that the same
security problem may exist in their schemes and also a malicious party can
reveal the other party's secret key without being detected by using the
Trojan-horse attacks. Accordingly, two basic properties of a quantum signature,
i.e. unforgeability and undeniability, may not be satisfied in their scheme
Mitigating Biased Activation in Weakly-supervised Object Localization via Counterfactual Learning
In this paper, we focus on an under-explored issue of biased activation in
prior weakly-supervised object localization methods based on Class Activation
Mapping (CAM). We analyze the cause of this problem from a causal view and
attribute it to the co-occurring background confounders. Following this
insight, we propose a novel Counterfactual Co-occurring Learning (CCL) paradigm
to synthesize the counterfactual representations via coupling constant
foreground and unrealized backgrounds in order to cut off their co-occurring
relationship. Specifically, we design a new network structure called
Counterfactual-CAM, which embeds the counterfactual representation perturbation
mechanism into the vanilla CAM-based model. This mechanism is responsible for
decoupling foreground as well as background and synthesizing the counterfactual
representations. By training the detection model with these synthesized
representations, we compel the model to focus on the constant foreground
content while minimizing the influence of distracting co-occurring background.
To our best knowledge, it is the first attempt in this direction. Extensive
experiments on several benchmarks demonstrate that Counterfactual-CAM
successfully mitigates the biased activation problem, achieving improved object
localization accuracy.Comment: 13 pages, 5 figures, 4 table
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