通过一系列联邦举措和命令,美国政府一直在努力确保美国在AI中的领导。这些广泛的战略文件影响了美国空军美国部(DAF)等组织。DAF-MIT AI加速器是DAF和MIT之间的一项计划,以弥合AI研究人员与DAF任务要求之间的差距。DAF-MIT AI加速器支持的几个项目正在开发公共挑战问题,这些问题解决了许多联邦AI研究的重点。这些挑战是通过公开可用的大型AI-Ready数据集,激励开源解决方案,并为可以激发进一步研究的双重使用技术创建需求信号,来针对优先事项。在本文中,我们描述了正在开发的这些公共挑战以及它们的应用如何促进科学进步。
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Neural Networks (GNNs) have revolutionized the molecular discovery to understand patterns and identify unknown features that can aid in predicting biophysical properties and protein-ligand interactions. However, current models typically rely on 2-dimensional molecular representations as input, and while utilization of 2\3- dimensional structural data has gained deserved traction in recent years as many of these models are still limited to static graph representations. We propose a novel approach based on the transformer model utilizing GNNs for characterizing dynamic features of protein-ligand interactions. Our message passing transformer pre-trains on a set of molecular dynamic data based off of physics-based simulations to learn coordinate construction and make binding probability and affinity predictions as a downstream task. Through extensive testing we compare our results with the existing models, our MDA-PLI model was able to outperform the molecular interaction prediction models with an RMSE of 1.2958. The geometric encodings enabled by our transformer architecture and the addition of time series data add a new dimensionality to this form of research.
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In the cybersecurity setting, defenders are often at the mercy of their detection technologies and subject to the information and experiences that individual analysts have. In order to give defenders an advantage, it is important to understand an attacker's motivation and their likely next best action. As a first step in modeling this behavior, we introduce a security game framework that simulates interplay between attackers and defenders in a noisy environment, focusing on the factors that drive decision making for attackers and defenders in the variants of the game with full knowledge and observability, knowledge of the parameters but no observability of the state (``partial knowledge''), and zero knowledge or observability (``zero knowledge''). We demonstrate the importance of making the right assumptions about attackers, given significant differences in outcomes. Furthermore, there is a measurable trade-off between false-positives and true-positives in terms of attacker outcomes, suggesting that a more false-positive prone environment may be acceptable under conditions where true-positives are also higher.
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Linear classifier probes are frequently utilized to better understand how neural networks function. Researchers have approached the problem of determining unit importance in neural networks by probing their learned, internal representations. Linear classifier probes identify highly selective units as the most important for network function. Whether or not a network actually relies on high selectivity units can be tested by removing them from the network using ablation. Surprisingly, when highly selective units are ablated they only produce small performance deficits, and even then only in some cases. In spite of the absence of ablation effects for selective neurons, linear decoding methods can be effectively used to interpret network function, leaving their effectiveness a mystery. To falsify the exclusive role of selectivity in network function and resolve this contradiction, we systematically ablate groups of units in subregions of activation space. Here, we find a weak relationship between neurons identified by probes and those identified by ablation. More specifically, we find that an interaction between selectivity and the average activity of the unit better predicts ablation performance deficits for groups of units in AlexNet, VGG16, MobileNetV2, and ResNet101. Linear decoders are likely somewhat effective because they overlap with those units that are causally important for network function. Interpretability methods could be improved by focusing on causally important units.
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定性概率网络(QPN)将贝叶斯网络的条件独立性假设与正相关的“定性”特性结合在一起。他们试图正式化正依赖性的各种直观属性,以允许对大型变量网络进行推断。但是,我们重点介绍了QPN文献中的一个关键错误,这意味着QPN做出的大多数推论在数学上不是正确的。我们还讨论了如何重新定义QPN以解决此问题。
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A deep learning strategy is developed for fast and accurate gas property measurements using flame emission spectroscopy (FES). Particularly, the short-gated fast FES is essential to resolve fast-evolving combustion behaviors. However, as the exposure time for capturing the flame emission spectrum gets shorter, the signal-to-noise ratio (SNR) decreases, and characteristic spectral features indicating the gas properties become relatively weaker. Then, the property estimation based on the short-gated spectrum is difficult and inaccurate. Denoising convolutional neural networks (CNN) can enhance the SNR of the short-gated spectrum. A new CNN architecture including a reversible down- and up-sampling (DU) operator and a loss function based on proper orthogonal decomposition (POD) coefficients is proposed. For training and testing the CNN, flame chemiluminescence spectra were captured from a stable methane-air flat flame using a portable spectrometer (spectral range: 250 - 850 nm, resolution: 0.5 nm) with varied equivalence ratio (0.8 - 1.2), pressure (1 - 10 bar), and exposure time (0.05, 0.2, 0.4, and 2 s). The long exposure (2 s) spectra were used as the ground truth when training the denoising CNN. A kriging model with POD is trained by the long-gated spectra for calibration, and then the prediction of the gas properties taking the denoised short-gated spectrum as the input: The property prediction errors of pressure and equivalence ratio were remarkably lowered in spite of the low SNR attendant with reduced exposure.
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本文研究了基于K最近邻居算法的专家系统的效力,用于激光散斑图像采样应用于早期检测糖尿病。利用人工智能引导激光散斑成像技术的最新发展,可以优化与合适的AI技术相关联的激光参数,例如波长,能级和图像纹理测量,以有效地与皮肤组织的亚细胞特性相互作用检测糖尿病的早期迹象。由于其优化的激光物理学和AI技术的优化组合,新方法可能比典型的皮肤葡萄糖水平观察更有效,并且另外,它允许非专家个人进行更频繁的皮肤组织测试以进行早期检测糖尿病。
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蛋白质 - 配体相互作用(PLIS)是生化研究的基础,其鉴定对于估计合理治疗设计的生物物理和生化特性至关重要。目前,这些特性的实验表征是最准确的方法,然而,这是非常耗时和劳动密集型的。在这种情况下已经开发了许多计算方法,但大多数现有PLI预测大量取决于2D蛋白质序列数据。在这里,我们提出了一种新颖的并行图形神经网络(GNN),以集成PLI预测的知识表示和推理,以便通过专家知识引导的深度学习,并通过3D结构数据通知。我们开发了两个不同的GNN架构,GNNF是采用不同特种的基础实现,以增强域名认识,而GNNP是一种新颖的实现,可以预测未经分子间相互作用的先验知识。综合评价证明,GNN可以成功地捕获配体和蛋白质3D结构之间的二元相互作用,对于GNNF的测试精度和0.958,用于预测蛋白质 - 配体络合物的活性。这些模型进一步适用于回归任务以预测实验结合亲和力,PIC50对于药物效力和功效至关重要。我们在实验亲和力上达到0.66和0.65的Pearson相关系数,分别在PIC50和GNNP上进行0.50和0.51,优于基于2D序列的模型。我们的方法可以作为可解释和解释的人工智能(AI)工具,用于预测活动,效力和铅候选的生物物理性质。为此,我们通过筛选大型复合库并将我们的预测与实验测量数据进行比较来展示GNNP对SARS-COV-2蛋白靶标的实用性。
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图像分类器通常在其测试设置精度上进行评分,但高精度可以屏蔽微妙类型的模型故障。我们发现高分卷积神经网络(CNNS)在流行的基准上表现出令人不安的病理,即使在没有语义突出特征的情况下,即使在没有语义突出特征的情况下也能够显示高精度。当模型提供没有突出的输入功能而无突出的频率决定时,我们说分类器已经过度解释了它的输入,找到了太多的课程 - 以对人类荒谬的模式。在这里,我们展示了在CiFar-10和Imagenet上培训的神经网络患有过度诠释,我们发现CIFAR-10上的模型即使在屏蔽95%的输入图像中,人类不能在剩余像素子集中辨别出突出的特征。我们介绍了批量梯度SIS,一种用于发现复杂数据集的足够输入子集的新方法,并使用此方法显示故事中的边界像素的充分性以进行培训和测试。虽然这些模式在现实世界部署中移植了潜在的模型脆弱性,但它们实际上是基准的有效统计模式,单独就足以实现高测试精度。与对手示例不同,过度解释依赖于未修改的图像像素。我们发现合奏和输入辍学可以帮助缓解过度诠释。
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疟疾是一种威胁生命的疾病,影响了数百万。基于显微镜的薄膜评估是(i)确定疟疾物种和(ii)定量高寄生虫感染的标准方法。通过机器学习(ML)对疟疾显微镜的完全自动化是一项具有挑战性的任务,因为预先准备的滑动在质量和表现方面差异很大,并且伪像通常超过相对较少的寄生虫。在这项工作中,我们描述了一个用于薄膜疟疾分析的完整,完全自动化的框架,该框架应用了ML方法,包括卷积神经网(CNN),该方法在大型且多样化的田间预先准备的薄膜数据集中进行了训练。定量和物种鉴定结果几乎足够准确地满足了耐药性监测和临床用例的混凝土需求。我们将方法和性能指标集中在现场用例要求上。我们讨论了将ML方法应用于疟疾显微镜的关键问题和重要指标。
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