在这项研究中,将放射学方法扩展到用于组织分类的光学荧光分子成像数据,称为“验光”。荧光分子成像正在出现在头颈部鳞状细胞癌(HNSCC)切除期间的精确手术引导。然而,肿瘤到正常的组织对比与靶分子表皮生长因子受体(EGFR)的异质表达的内在生理局限性混淆。验光学试图通过探测荧光传达的EGFR表达中的质地模式差异来改善肿瘤识别。从荧光图像样品中提取了总共1,472个标准化的验光特征。涉及支持矢量机分类器的监督机器学习管道接受了25个顶级功能的培训,这些功能由最小冗余最大相关标准选择。通过将切除组织的图像贴片分类为组织学确认的恶性肿瘤状态,将模型预测性能与荧光强度阈值方法进行了比较。与荧光强度阈值方法相比,验光方法在所有测试集样品中提供了一致的预测准确性(无剂量)(平均精度为89%vs. 81%; P = 0.0072)。改进的性能表明,将放射线学方法扩展到荧光分子成像数据为荧光引导手术中的癌症检测提供了有希望的图像分析技术。
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With an ever-growing number of parameters defining increasingly complex networks, Deep Learning has led to several breakthroughs surpassing human performance. As a result, data movement for these millions of model parameters causes a growing imbalance known as the memory wall. Neuromorphic computing is an emerging paradigm that confronts this imbalance by performing computations directly in analog memories. On the software side, the sequential Backpropagation algorithm prevents efficient parallelization and thus fast convergence. A novel method, Direct Feedback Alignment, resolves inherent layer dependencies by directly passing the error from the output to each layer. At the intersection of hardware/software co-design, there is a demand for developing algorithms that are tolerable to hardware nonidealities. Therefore, this work explores the interrelationship of implementing bio-plausible learning in-situ on neuromorphic hardware, emphasizing energy, area, and latency constraints. Using the benchmarking framework DNN+NeuroSim, we investigate the impact of hardware nonidealities and quantization on algorithm performance, as well as how network topologies and algorithm-level design choices can scale latency, energy and area consumption of a chip. To the best of our knowledge, this work is the first to compare the impact of different learning algorithms on Compute-In-Memory-based hardware and vice versa. The best results achieved for accuracy remain Backpropagation-based, notably when facing hardware imperfections. Direct Feedback Alignment, on the other hand, allows for significant speedup due to parallelization, reducing training time by a factor approaching N for N-layered networks.
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Recent work has shown that machine learning (ML) models can be trained to accurately forecast the dynamics of unknown chaotic dynamical systems. Such ML models can be used to produce both short-term predictions of the state evolution and long-term predictions of the statistical patterns of the dynamics (``climate''). Both of these tasks can be accomplished by employing a feedback loop, whereby the model is trained to predict forward one time step, then the trained model is iterated for multiple time steps with its output used as the input. In the absence of mitigating techniques, however, this technique can result in artificially rapid error growth, leading to inaccurate predictions and/or climate instability. In this article, we systematically examine the technique of adding noise to the ML model input during training as a means to promote stability and improve prediction accuracy. Furthermore, we introduce Linearized Multi-Noise Training (LMNT), a regularization technique that deterministically approximates the effect of many small, independent noise realizations added to the model input during training. Our case study uses reservoir computing, a machine-learning method using recurrent neural networks, to predict the spatiotemporal chaotic Kuramoto-Sivashinsky equation. We find that reservoir computers trained with noise or with LMNT produce climate predictions that appear to be indefinitely stable and have a climate very similar to the true system, while reservoir computers trained without regularization are unstable. Compared with other types of regularization that yield stability in some cases, we find that both short-term and climate predictions from reservoir computers trained with noise or with LMNT are substantially more accurate. Finally, we show that the deterministic aspect of our LMNT regularization facilitates fast hyperparameter tuning when compared to training with noise.
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We study the problem of model selection in causal inference, specifically for the case of conditional average treatment effect (CATE) estimation under binary treatments. Unlike model selection in machine learning, we cannot use the technique of cross-validation here as we do not observe the counterfactual potential outcome for any data point. Hence, we need to design model selection techniques that do not explicitly rely on counterfactual data. As an alternative to cross-validation, there have been a variety of proxy metrics proposed in the literature, that depend on auxiliary nuisance models also estimated from the data (propensity score model, outcome regression model). However, the effectiveness of these metrics has only been studied on synthetic datasets as we can observe the counterfactual data for them. We conduct an extensive empirical analysis to judge the performance of these metrics, where we utilize the latest advances in generative modeling to incorporate multiple realistic datasets. We evaluate 9 metrics on 144 datasets for selecting between 415 estimators per dataset, including datasets that closely mimic real-world datasets. Further, we use the latest techniques from AutoML to ensure consistent hyperparameter selection for nuisance models for a fair comparison across metrics.
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检测和避免(DAA)功能对于无人飞机系统(UAS)的安全操作至关重要。本文介绍了Airtrack,这是一个仅实时视觉检测和跟踪框架,尊重SUAS系统的大小,重量和功率(交换)约束。鉴于遥远飞机的低信噪比(SNR),我们建议在深度学习框架中使用完整的分辨率图像,以对齐连续的图像以消除自我动态。然后,对齐的图像在级联的初级和次级分类器中下游使用,以改善多个指标的检测和跟踪性能。我们表明,Airtrack在亚马逊机载对象跟踪(AOT)数据集上胜过最先进的基线。多次现实世界的飞行测试与CESSNA 172与通用航空交通相互作用,并在受控的设置中朝着UAS飞向UAS的其他近碰撞飞行测试,该拟议方法满足了新引入的ASTM F3442/F3442M标准DAA标准。经验评估表明,我们的系统的概率超过900m,范围超过95%。视频可在https://youtu.be/h3ll_wjxjpw上找到。
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无人驾驶汽车(UAV)在许多领域都受雇于摄影,紧急,娱乐,国防,农业,林业,采矿和建筑。在过去的十年中,无人机技术在许多施工项目阶段中找到了应用程序,从现场映射,进度监控,建筑物检查,损坏评估和材料交付等等。尽管已经对无人机在各种施工相关的过程中的优势进行了广泛的研究,但关于提高任务能力和效率的无人机协作的研究仍然很少。本文提出了一种基于塔格狩猎游戏和粒子群优化(PSO)的多个无人机的新合作路径计划算法。首先,定义了每个无人机的成本函数,并包含多个目标和约束。然后,开发了无人机游戏框架,以将多功能路径计划制定到寻找回报优势均衡的问题。接下来,提出了基于PSO的算法来获得无人机的最佳路径。由三个无人机检查的大型建筑工地的仿真结果表明,在检查任务期间,提出的算法在为无人机形成的可行和高效飞行路径生成可行,高效的飞行路径上的有效性。
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离线增强学习(RL)旨在使用先前收集的静态数据集学习最佳策略,是RL的重要范式。由于函数近似错误在分布外动作上的功能近似错误,因此在此任务上的标准RL方法通常会表现较差。尽管已经提出了各种正规化方法来减轻此问题,但它们通常受到表达有限的策略类别的限制,有时会导致次优的解决方案。在本文中,我们提出了利用条件扩散模型作为行为克隆和策略正则化的高度表达政策类别的扩散-QL。在我们的方法中,我们学习了一个动作值函数,并在有条件扩散模型的训练损失中添加了最大化动作值的术语,这导致损失寻求接近行为政策的最佳动作。我们展示了基于扩散模型的策略的表现力以及在扩散模型下的行为克隆和策略改进的耦合都有助于扩散-QL的出色性能。我们在具有多模式行为策略的简单2D强盗示例中说明了我们的方法和先前的工作。然后,我们证明我们的方法可以在离线RL的大多数D4RL基准任务上实现最先进的性能。
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本文介绍了频率卷积神经网络(CNN),用于快速,无创的​​2D剪切波速度(VS)成像的近表面地质材料。在频速度域中运行,可以在用于生成CNN输入的线性阵列,主动源实验测试配置中具有显着的灵活性,这些配置是归一化的分散图像。与波场图像不同,标准化的分散图像对实验测试配置相对不敏感,可容纳各种源类型,源偏移,接收器数量和接收器间距。我们通过将其应用于经典的近乎表面地球物理学问题,即成像两层,起伏的土壤 - 旁质界面的界面来证明频率CNN的有效性。最近,通过开发一个时间距离CNN来研究这个问题,该问题表现出了很大的希望,但在使用不同的现场测试配置方面缺乏灵活性。本文中,新的频道CNN显示出与时距CNN的可比精度,同时提供了更大的灵活性来处理各种现场应用程序。使用100,000个合成近表面模型对频率速度CNN进行了训练,验证和测试。首先,使用训练集的合成近表面模型测试了提议的频率CNN跨各种采集配置概括跨各种采集配置的能力,然后应用于在Austin的Hornsby Bend在Austin的Hornsby Bend收集的实验场数据美国德克萨斯州,美国。当针对更广泛的地质条件范围充分开发时,提出的CNN最终可以用作当前伪2D表面波成像技术的快速,端到端替代方案,或开发用于完整波形倒置的启动模型。
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我们展示了一种物理感知的变压器,用于从具有不同分辨率,颜色空间,焦距,焦距和暴露的相机的基于特征的数据融合。我们还展示了使用开源计算机图形软件为变压器合成训练数据生成的可扩展解决方案。我们演示了具有不同光谱响应,瞬时视野和框架速率的阵列上的图像合成。
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要使用深神经网络预测罕见的极端事件,一个人遇到所谓的小数据问题,因为即使是长期观测通常常见的事件常见。在这里,我们研究了一种模型辅助框架,其中训练数据是从数值模拟获得的,而不是观察,具有来自极端事件的适当样本。但是,为了确保培训的网络在实践中适用,无法在完整的仿真数据上执行培训;相反,我们只使用可以在实践中测量的可观察量的小子集。我们调查这一模型辅助框架在三种不同动力系统(Rossler Larguger Or,Fitzhugh - Nagumo Model和湍流流体流量)和三种不同的深神经网络架构(前馈,长短期内存和储层计算)上的可行性)。在每种情况下,我们研究了预测准确性,稳健性对噪声,重复训练的再现性,以及对输入数据类型的敏感性。特别是,我们发现长期的短期内存网络是最强大的噪声,并产生相对准确的预测,同时需要最小的高考的微调。
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