增加片上光子神经网络(PNN)的层数对于改善其模型性能至关重要。但是,网络隐藏层的连续级联导致更大的集成光子芯片区域。为了解决此问题,我们提出了光学神经常规微分方程(ON-ON-ON-OD-ON-OD-ON-OD-ON-OD-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ODINE),该架构用光ODE求解器参数化了隐藏层的连续动力学。 On-Ode包括PNN,然后是光子积分器和光反馈回路,可以配置为代表残留的神经网络(RESNET)和复发性神经网络,并有效地降低了芯片面积占用率。对于基于干扰的光电非线性隐藏层,数值实验表明,单个隐藏层ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ON-ONE表示与图像分类任务中的两层光学重新系统大致相同。此外,Onode提高了基于衍射的全光线性隐藏层的模型分类精度。 On-Eod的时间依赖性动力学属性进一步应用于高精度的轨迹预测。
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特定的发射极识别(SEI)是物理层身份验证的高潜在技术,它是上层身份验证的最关键补充之一。 SEI基于电路差而不是密码学的射频(RF)特征。这些功能是硬件电路的固有特征,很难伪造。最近,已经提出了各种基于深度学习(DL)的常规SEI方法,并实现了高级性能。但是,提出了这些方法,用于使用大量的RF信号样品进行训练的近距离场景,并且在训练样品有限的情况下,它们的性能较差。因此,我们将重点放在几个射击SEI(FS-SEI)上,用于通过自动依赖的监视播(ADS-B)信号进行飞机识别,并根据深度度量集合学习(DMEL)提出了一种新颖的FS-SEI方法。具体而言,提出的方法包括特征嵌入和分类。前者基于具有复杂价值的卷积神经网络(CVCNN)的度量学习,用于提取具有紧凑的类别内距离和可分离类别间距离的区分特征,而后者则由集合分类器实现。仿真结果表明,如果每个类别的样本数量超过5,则我们提出的方法的平均准确性高于98 \%。此外,特征可视化证明了我们提出的方法在可区分性和概括方面的优势。本文的代码可以从GitHub(https://github.com/beechburgpiestar/few-shot-specific-emitter-emitter-istifification-via-deep-metric-metric-semble-learning)下载。
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神经网络已广泛应用于垃圾邮件和网络钓鱼检测,入侵预防和恶意软件检测等安全应用程序。但是,这种黑盒方法通常在应用中具有不确定性和不良的解释性。此外,神经网络本身通常容易受到对抗攻击的影响。由于这些原因,人们对可信赖和严格的方法有很高的需求来验证神经网络模型的鲁棒性。对抗性的鲁棒性在处理恶意操纵输入时涉及神经网络的可靠性,是安全和机器学习中最热门的主题之一。在这项工作中,我们在神经网络的对抗性鲁棒性验证中调查了现有文献,并在机器学习,安全和软件工程领域收集了39项多元化研究工作。我们系统地分析了它们的方法,包括如何制定鲁棒性,使用哪种验证技术以及每种技术的优势和局限性。我们从正式验证的角度提供分类学,以全面理解该主题。我们根据财产规范,减少问题和推理策略对现有技术进行分类。我们还展示了使用样本模型在现有研究中应用的代表性技术。最后,我们讨论了未来研究的开放问题。
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全球和本地环境显着有助于显着对象检测(SOD)中预测的完整性。不幸的是,现有的方法仍然难以生成完整的预测,并提供细节。常规方法中有两个主要问题:首先,对于全球环境,高级CNN的编码器功能无法有效地捕获长期依赖性,从而导致不完整的预测。其次,将地面真相的采样降低以适应预测的规模,因为在插值或合并过程中丢失了地面真相细节,因此会引起不准确性。因此,在这项工作中,我们开发了一个基于变压器的网络,并构成了分支机构的监督任务,以明确学习全局上下文信息。此外,我们采用从超级分辨率(SR)的像素随机散发,将预测重塑为地面真理的大小,而不是反向。因此,地面真理中的细节没有触及。此外,我们开发了一个两阶段的上下文改进模块(CRM)来融合全局上下文,并自动在预测中找到和完善本地细节。拟议的网络可以根据生成的全局和本地上下文(因此被命名为自我精制的变压器)(自我改革)指导和纠正自身。五个基准数据集的广泛实验和评估结果证明了网络的出色性能,我们实现了最新的技术。
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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.
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According to the rapid development of drone technologies, drones are widely used in many applications including military domains. In this paper, a novel situation-aware DRL- based autonomous nonlinear drone mobility control algorithm in cyber-physical loitering munition applications. On the battlefield, the design of DRL-based autonomous control algorithm is not straightforward because real-world data gathering is generally not available. Therefore, the approach in this paper is that cyber-physical virtual environment is constructed with Unity environment. Based on the virtual cyber-physical battlefield scenarios, a DRL-based automated nonlinear drone mobility control algorithm can be designed, evaluated, and visualized. Moreover, many obstacles exist which is harmful for linear trajectory control in real-world battlefield scenarios. Thus, our proposed autonomous nonlinear drone mobility control algorithm utilizes situation-aware components those are implemented with a Raycast function in Unity virtual scenarios. Based on the gathered situation-aware information, the drone can autonomously and nonlinearly adjust its trajectory during flight. Therefore, this approach is obviously beneficial for avoiding obstacles in obstacle-deployed battlefields. Our visualization-based performance evaluation shows that the proposed algorithm is superior from the other linear mobility control algorithms.
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Multivariate time series forecasting with hierarchical structure is pervasive in real-world applications, demanding not only predicting each level of the hierarchy, but also reconciling all forecasts to ensure coherency, i.e., the forecasts should satisfy the hierarchical aggregation constraints. Moreover, the disparities of statistical characteristics between levels can be huge, worsened by non-Gaussian distributions and non-linear correlations. To this extent, we propose a novel end-to-end hierarchical time series forecasting model, based on conditioned normalizing flow-based autoregressive transformer reconciliation, to represent complex data distribution while simultaneously reconciling the forecasts to ensure coherency. Unlike other state-of-the-art methods, we achieve the forecasting and reconciliation simultaneously without requiring any explicit post-processing step. In addition, by harnessing the power of deep model, we do not rely on any assumption such as unbiased estimates or Gaussian distribution. Our evaluation experiments are conducted on four real-world hierarchical datasets from different industrial domains (three public ones and a dataset from the application servers of Alipay's data center) and the preliminary results demonstrate efficacy of our proposed method.
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Large language models (LLMs) have demonstrated impressive capabilities in natural language understanding and generation, but the quality bar for medical and clinical applications is high. Today, attempts to assess models' clinical knowledge typically rely on automated evaluations on limited benchmarks. There is no standard to evaluate model predictions and reasoning across a breadth of tasks. To address this, we present MultiMedQA, a benchmark combining six existing open question answering datasets spanning professional medical exams, research, and consumer queries; and HealthSearchQA, a new free-response dataset of medical questions searched online. We propose a framework for human evaluation of model answers along multiple axes including factuality, precision, possible harm, and bias. In addition, we evaluate PaLM (a 540-billion parameter LLM) and its instruction-tuned variant, Flan-PaLM, on MultiMedQA. Using a combination of prompting strategies, Flan-PaLM achieves state-of-the-art accuracy on every MultiMedQA multiple-choice dataset (MedQA, MedMCQA, PubMedQA, MMLU clinical topics), including 67.6% accuracy on MedQA (US Medical License Exam questions), surpassing prior state-of-the-art by over 17%. However, human evaluation reveals key gaps in Flan-PaLM responses. To resolve this we introduce instruction prompt tuning, a parameter-efficient approach for aligning LLMs to new domains using a few exemplars. The resulting model, Med-PaLM, performs encouragingly, but remains inferior to clinicians. We show that comprehension, recall of knowledge, and medical reasoning improve with model scale and instruction prompt tuning, suggesting the potential utility of LLMs in medicine. Our human evaluations reveal important limitations of today's models, reinforcing the importance of both evaluation frameworks and method development in creating safe, helpful LLM models for clinical applications.
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Vision Transformers have shown great promise recently for many vision tasks due to the insightful architecture design and attention mechanism. By revisiting the self-attention responses in Transformers, we empirically observe two interesting issues. First, Vision Transformers present a queryirrelevant behavior at deep layers, where the attention maps exhibit nearly consistent contexts in global scope, regardless of the query patch position (also head-irrelevant). Second, the attention maps are intrinsically sparse, few tokens dominate the attention weights; introducing the knowledge from ConvNets would largely smooth the attention and enhance the performance. Motivated by above observations, we generalize self-attention formulation to abstract a queryirrelevant global context directly and further integrate the global context into convolutions. The resulting model, a Fully Convolutional Vision Transformer (i.e., FCViT), purely consists of convolutional layers and firmly inherits the merits of both attention mechanism and convolutions, including dynamic property, weight sharing, and short- and long-range feature modeling, etc. Experimental results demonstrate the effectiveness of FCViT. With less than 14M parameters, our FCViT-S12 outperforms related work ResT-Lite by 3.7% top1 accuracy on ImageNet-1K. When scaling FCViT to larger models, we still perform better than previous state-of-the-art ConvNeXt with even fewer parameters. FCViT-based models also demonstrate promising transferability to downstream tasks, like object detection, instance segmentation, and semantic segmentation. Codes and models are made available at: https://github.com/ma-xu/FCViT.
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Language models (LMs) have demonstrated remarkable performance on downstream tasks, using in-context exemplars or human instructions. Recent works have shown that chain-of-thought (CoT) prompting can elicit models to solve complex reasoning tasks, step-by-step. However, the efficacy of prompt-based CoT methods is restricted to very large LMs such as GPT-3 (175B), thus limiting deployability. In this paper, we revisit the fine-tuning approach to enable complex reasoning in smaller LMs, optimized to efficiently perform a specific task. We propose Fine-tune-CoT, a method that leverages the capabilities of very large LMs to generate reasoning samples and teach smaller models via fine-tuning. We evaluate our method on publicly available LMs across a wide range of complex tasks and model sizes. We find that Fine-tune-CoT enables substantial reasoning capability in small models, whereas previous prompt-based baselines exhibit near-random performance. Student models can even outperform the teacher in some tasks while reducing model size requirements by several orders of magnitude. We conduct extensive ablations and sample studies to understand the reasoning capabilities of student models. We also identify several important nuances that have been overlooked in concurrent fine-tuning works on CoT and address them in our analysis.
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