A central problem in computational biophysics is protein structure prediction, i.e., finding the optimal folding of a given amino acid sequence. This problem has been studied in a classical abstract model, the HP model, where the protein is modeled as a sequence of H (hydrophobic) and P (polar) amino acids on a lattice. The objective is to find conformations maximizing H-H contacts. It is known that even in this reduced setting, the problem is intractable (NP-hard). In this work, we apply deep reinforcement learning (DRL) to the two-dimensional HP model. We can obtain the conformations of best known energies for benchmark HP sequences with lengths from 20 to 50. Our DRL is based on a deep Q-network (DQN). We find that a DQN based on long short-term memory (LSTM) architecture greatly enhances the RL learning ability and significantly improves the search process. DRL can sample the state space efficiently, without the need of manual heuristics. Experimentally we show that it can find multiple distinct best-known solutions per trial. This study demonstrates the effectiveness of deep reinforcement learning in the HP model for protein folding.

内存处理（PIM）是一种越来越多地研究的神经形态硬件，承诺能量和吞吐量改进以进行深度学习推断。 PIM利用大量平行，有效的模拟计算在内存内部，绕过传统数字硬件中数据移动的瓶颈。但是，需要额外的量化步骤（即PIM量化），通常由于硬件约束而导致的分辨率有限，才能将模拟计算结果转换为数字域。同时，由于不完善的类似物到数字界面，PIM量化中的非理想效应广泛存在，这进一步损害了推理的准确性。在本文中，我们提出了一种培训量化网络的方法，以合并PIM量化，这对所有PIM系统无处不在。具体而言，我们提出了PIM量化意识培训（PIM-QAT）算法，并通过分析训练动力学以促进训练收敛，从而在向后传播期间引入重新传播技术。我们还提出了两种技术，即批处理归一化（BN）校准和调整精度训练，以抑制实际PIM芯片中涉及的非理想线性和随机热噪声的不利影响。我们的方法在三个主流PIM分解方案上进行了验证，并在原型芯片上进行了物理上的验证。与直接在PIM系统上部署常规训练的量化模型相比，该模型没有考虑到此额外的量化步骤并因此失败，我们的方法提供了重大改进。它还可以在CIFAR10和CIFAR100数据集上使用各种网络深度来获得最受欢迎的网络拓扑结构，在CIFAR10和CIFAR100数据集上，在PIM系统上达到了可比的推理精度。

结构化的修剪技术在用于图像分类任务的卷积神经网络上取得了出色的压缩性能。但是，大多数现有方法都是面向重量的，当原始模型的训练不佳时，它们的修剪结果可能不令人满意。也就是说，需要一个全面训练的模型来提供有用的权重信息。这可能是耗时的，并且修剪结果对模型参数的更新过程敏感。在本文中，我们提出了一个名为“平均过滤器信息熵（AFIE）”的度量，以测量每个滤镜的重要性。它是由三个主要步骤计算得出的，即每个卷积层的“输入输出”矩阵的低排放分解，所获得的特征值的归一化以及基于信息熵的滤波器重要性计算。通过利用拟议的AFIE，无论是否完全训练原始模型，建议的框架都能对每个过滤器进行稳定的重要性评估。我们基于Alexnet，VGG-16和Resnet-50实施AFIE，并分别对MNIST，CIFAR-10和Imagenet进行测试。实验结果令人鼓舞。我们出乎意料地观察到，对于我们的方法，即使原始模型仅经过一个时代的训练，每个过滤器的重要性评估在模型经过全面训练时都与结果相同。这表明拟议的修剪策略可以在原始模型的训练过程的开始阶段有效地执行。

Trajectory prediction is an integral component of modern autonomous systems as it allows for envisioning future intentions of nearby moving agents. Due to the lack of other agents' dynamics and control policies, deep neural network (DNN) models are often employed for trajectory forecasting tasks. Although there exists an extensive literature on improving the accuracy of these models, there is a very limited number of works studying their robustness against adversarially crafted input trajectories. To bridge this gap, in this paper, we propose a targeted adversarial attack against DNN models for trajectory forecasting tasks. We call the proposed attack TA4TP for Targeted adversarial Attack for Trajectory Prediction. Our approach generates adversarial input trajectories that are capable of fooling DNN models into predicting user-specified target/desired trajectories. Our attack relies on solving a nonlinear constrained optimization problem where the objective function captures the deviation of the predicted trajectory from a target one while the constraints model physical requirements that the adversarial input should satisfy. The latter ensures that the inputs look natural and they are safe to execute (e.g., they are close to nominal inputs and away from obstacles). We demonstrate the effectiveness of TA4TP on two state-of-the-art DNN models and two datasets. To the best of our knowledge, we propose the first targeted adversarial attack against DNN models used for trajectory forecasting.

修剪技术可全面使用图像分类压缩卷积神经网络（CNN）。但是，大多数修剪方法需要一个经过良好训练的模型，以提供有用的支持参数，例如C1-核心，批处理值和梯度信息，如果预训练的模型的参数为，这可能会导致过滤器评估的不一致性不太优化。因此，我们提出了一种基于敏感性的方法，可以通过为原始模型增加额外的损害来评估每一层的重要性。由于准确性的性能取决于参数在所有层而不是单个参数中的分布，因此基于灵敏度的方法将对参数的更新具有鲁棒性。也就是说，我们可以获得对不完美训练和完全训练的模型之间每个卷积层的相似重要性评估。对于CIFAR-10上的VGG-16，即使原始模型仅接受50个时期训练，我们也可以对层的重要性进行相同的评估，并在对模型进行充分训练时的结果。然后，我们将通过量化的灵敏度从每一层中删除过滤器。我们基于敏感性的修剪框架在VGG-16，分别具有CIFAR-10，MNIST和CIFAR-100的VGG-16上有效验证。

近年来，图形变压器在各种图形学习任务上表现出了优势。但是，现有图形变压器的复杂性与节点的数量二次缩放，因此难以扩展到具有数千个节点的图形。为此，我们提出了一个邻域聚集图变压器（Nagphormer），该变压器可扩展到具有数百万节点的大图。在将节点特征馈送到变压器模型中之前，Nagphormer构造令牌由称为Hop2Token的邻域聚合模块为每个节点。对于每个节点，Hop2token聚合从每个跳跃到表示形式的邻域特征，从而产生一系列令牌向量。随后，不同HOP信息的结果序列是变压器模型的输入。通过将每个节点视为一个序列，可以以迷你批量的方式训练Nagphormer，从而可以扩展到大图。 Nagphormer进一步开发了基于注意力的读数功能，以便学习每个跳跃的重要性。我们在各种流行的基准测试中进行了广泛的实验，包括六个小数据集和三个大数据集。结果表明，Nagphormer始终优于现有的图形变压器和主流图神经网络。

尽管取得了巨大的成功，但深入的学习严重遭受鲁棒性;也就是说，深度神经网络非常容易受到对抗的攻击，即使是最简单的攻击。灵感来自脑科学最近的进步，我们提出了一种新的内部模型（DIM），这是一种基于新的生成自动化器的模型来解决这一挑战。模拟人类大脑中的管道进行视觉信号处理，暗淡采用两级方法。在第一阶段，DIM使用丹组器来减少输入的噪声和尺寸，反映了塔马拉姆的信息预处理。从主视觉皮质中的内存相关迹线的稀疏编码启发，第二阶段产生一组内部模型，一个用于每个类别。我们评估了42次对抗攻击的衰弱，表明Dim有效地防御所有攻击，并且优于整体鲁棒性的SOTA。

This study provides a new understanding of the adversarial attack problem by examining the correlation between adversarial attack and visual attention change. In particular, we observed that: (1) images with incomplete attention regions are more vulnerable to adversarial attacks; and (2) successful adversarial attacks lead to deviated and scattered attention map. Accordingly, an attention-based adversarial defense framework is designed to simultaneously rectify the attention map for prediction and preserve the attention area between adversarial and original images. The problem of adding iteratively attacked samples is also discussed in the context of visual attention change. We hope the attention-related data analysis and defense solution in this study will shed some light on the mechanism behind the adversarial attack and also facilitate future adversarial defense/attack model design.

Dataset distillation has emerged as a prominent technique to improve data efficiency when training machine learning models. It encapsulates the knowledge from a large dataset into a smaller synthetic dataset. A model trained on this smaller distilled dataset can attain comparable performance to a model trained on the original training dataset. However, the existing dataset distillation techniques mainly aim at achieving the best trade-off between resource usage efficiency and model utility. The security risks stemming from them have not been explored. This study performs the first backdoor attack against the models trained on the data distilled by dataset distillation models in the image domain. Concretely, we inject triggers into the synthetic data during the distillation procedure rather than during the model training stage, where all previous attacks are performed. We propose two types of backdoor attacks, namely NAIVEATTACK and DOORPING. NAIVEATTACK simply adds triggers to the raw data at the initial distillation phase, while DOORPING iteratively updates the triggers during the entire distillation procedure. We conduct extensive evaluations on multiple datasets, architectures, and dataset distillation techniques. Empirical evaluation shows that NAIVEATTACK achieves decent attack success rate (ASR) scores in some cases, while DOORPING reaches higher ASR scores (close to 1.0) in all cases. Furthermore, we conduct a comprehensive ablation study to analyze the factors that may affect the attack performance. Finally, we evaluate multiple defense mechanisms against our backdoor attacks and show that our attacks can practically circumvent these defense mechanisms.

Blind image quality assessment (BIQA) remains challenging due to the diversity of distortion and image content variation, which complicate the distortion patterns crossing different scales and aggravate the difficulty of the regression problem for BIQA. However, existing BIQA methods often fail to consider multi-scale distortion patterns and image content, and little research has been done on learning strategies to make the regression model produce better performance. In this paper, we propose a simple yet effective Progressive Multi-Task Image Quality Assessment (PMT-IQA) model, which contains a multi-scale feature extraction module (MS) and a progressive multi-task learning module (PMT), to help the model learn complex distortion patterns and better optimize the regression issue to align with the law of human learning process from easy to hard. To verify the effectiveness of the proposed PMT-IQA model, we conduct experiments on four widely used public datasets, and the experimental results indicate that the performance of PMT-IQA is superior to the comparison approaches, and both MS and PMT modules improve the model's performance.