Large language models (LLMs) have been shown to be able to perform new tasks based on a few demonstrations or natural language instructions. While these capabilities have led to widespread adoption, most LLMs are developed by resource-rich organizations and are frequently kept from the public. As a step towards democratizing this powerful technology, we present BLOOM, a 176B-parameter open-access language model designed and built thanks to a collaboration of hundreds of researchers. BLOOM is a decoder-only Transformer language model that was trained on the ROOTS corpus, a dataset comprising hundreds of sources in 46 natural and 13 programming languages (59 in total). We find that BLOOM achieves competitive performance on a wide variety of benchmarks, with stronger results after undergoing multitask prompted finetuning. To facilitate future research and applications using LLMs, we publicly release our models and code under the Responsible AI License.
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现有的数据驱动和反馈流量控制策略不考虑实时数据测量的异质性。此外,对于缺乏数据效率,传统的加固学习方法(RL)方法通常会缓慢收敛。此外,常规的最佳外围控制方案需要对系统动力学的精确了解,因此对内源性不确定性会很脆弱。为了应对这些挑战,这项工作提出了一种基于不可或缺的增强学习(IRL)的方法来学习宏观交通动态,以进行自适应最佳周边控制。这项工作为运输文献做出了以下主要贡献:(a)开发连续的时间控制,并具有离散增益更新以适应离散时间传感器数据。 (b)为了降低采样复杂性并更有效地使用可用数据,将体验重播(ER)技术引入IRL算法。 (c)所提出的方法以“无模型”方式放松模型校准的要求,该方式可以稳健地进行建模不确定性,并通过数据驱动的RL算法增强实时性能。 (d)通过Lyapunov理论证明了基于IRL的算法和受控交通动力学的稳定性的收敛性。最佳控制定律被参数化,然后通过神经网络(NN)近似,从而缓解计算复杂性。在不需要模型线性化的同时,考虑了状态和输入约束。提出了数值示例和仿真实验,以验证所提出方法的有效性和效率。
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虽然外源变量对时间序列分析的性能改善有重大影响,但在当前的连续方法中很少考虑这些序列间相关性和时间依赖性。多元时间序列的动力系统可以用复杂的未知偏微分方程(PDE)进行建模,这些方程(PDE)在科学和工程的许多学科中都起着重要作用。在本文中,我们提出了一个任意步骤预测的连续时间模型,以学习多元时间序列中的未知PDE系统,其管理方程是通过自我注意和封闭的复发神经网络参数化的。所提出的模型\下划线{变量及其对目标系列的影响。重要的是,使用特殊设计的正则化指南可以将模型简化为正则化的普通微分方程(ODE)问题,这使得可以触犯的PDE问题以获得数值解决方案,并且可行,以预测目标序列的多个未来值。广泛的实验表明,我们提出的模型可以在强大的基准中实现竞争精度:平均而言,它通过降低RMSE的$ 9.85 \%$和MAE的MAE $ 13.98 \%$的基线表现优于最佳基准,以获得任意步骤预测的MAE $。
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血管内操作中的自主机器人有可能安全可靠地浏览循环系统,同时降低对人体错误的敏感性。但是,训练机器人的过程涉及许多挑战,例如由于机器学习算法的效率低下而导致的长期培训持续时间以及导管与血管内幻影之间的相互作用引起的安全问题。物理模拟器已在血管内手术的背景下使用,但通常用于员工培训,通常不符合自主插管目标。此外,大多数当前的模拟器都是封闭消息,它阻碍了安全可靠的自主系统的协作开发。在这项工作中,我们介绍了Cathsim,Cathsim是一种开源模拟环境,可加快用于自主内血管内导航的机器学习算法的开发。我们首先使用最先进的血管内机器人模拟高保真导管和主动脉。然后,我们在模拟环境中提供了导管和主动脉之间实时力传感的能力。我们通过使用两种流行的强化学习算法,近端策略优化(PPO)和软参与者(SAC)在两个主要动脉内执行两个不同的导管插入任务来验证我们的模拟器。实验结果表明,使用我们的开源模拟器,我们可以成功训练增强型学习剂以执行不同的自主插管任务。
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Federated Learning是一个私人设计的分布式学习范式,客户在中央服务器汇总本地更新以计算全局模型之前,客户在自己的数据上训练本地模型。根据所使用的聚合方法,本地更新是本地学习模型的梯度或权重。最近的重建攻击对单个MiniBatch的梯度更新应用了梯度反演优化,以重建客户在培训期间使用的私人数据。由于最新的重建攻击仅关注单个更新,因此忽略了现实的对抗场景,例如跨多个小型批次训练的多个更新和更新。一些研究考虑了一个更具挑战性的对抗场景,在该场景中,只能根据多个迷你批次进行模型更新,并且可以观察到计算昂贵的模拟,以解开每个本地步骤的基本样本。在本文中,我们提出了一种新型的近似梯度反转攻击,可有效,有效地重建来自模型或梯度更新的图像,以及跨多个时期。简而言之,agic(i)近似于模型更新中使用的训练样本的梯度更新,以避免昂贵的仿真程序,(ii)利用从多个时期收集的梯度/模型更新,(iii)将权重增加到相对于层的重量增加重建质量的神经网络结构。我们在三个数据集CIFAR-10,CIFAR-100和Imagenet上广泛评估AGIC。我们的结果表明,与两种代表性的最先进的梯度反演攻击相比,AGIC将峰值信噪比(PSNR)提高了50%。此外,AGIC的速度比基于最新的模拟攻击快,例如,在模型更新之间使用8个本地步骤攻击FedAvg时,它的速度快5倍。
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In many applications, it is of interest to identify a parsimonious set of features, or panel, from multiple candidates that achieves a desired level of performance in predicting a response. This task is often complicated in practice by missing data arising from the sampling design or other random mechanisms. Most recent work on variable selection in missing data contexts relies in some part on a finite-dimensional statistical model, e.g., a generalized or penalized linear model. In cases where this model is misspecified, the selected variables may not all be truly scientifically relevant and can result in panels with suboptimal classification performance. To address this limitation, we propose a nonparametric variable selection algorithm combined with multiple imputation to develop flexible panels in the presence of missing-at-random data. We outline strategies based on the proposed algorithm that achieve control of commonly used error rates. Through simulations, we show that our proposal has good operating characteristics and results in panels with higher classification and variable selection performance compared to several existing penalized regression approaches in cases where a generalized linear model is misspecified. Finally, we use the proposed method to develop biomarker panels for separating pancreatic cysts with differing malignancy potential in a setting where complicated missingness in the biomarkers arose due to limited specimen volumes.
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虽然大多数当前的图像支出都进行了水平外推,但我们研究了广义图像支出问题,这些问题将视觉上下文推断出给定图像周围的全面。为此,我们开发了一个新型的基于变压器的生成对抗网络,称为U-Transformer,能够扩展具有合理结构和细节的图像边界,即使是复杂的风景图像。具体而言,我们将生成器设计为嵌入流行的Swin Transformer块的编码器到二次结构。因此,我们的新型框架可以更好地应对图像远程依赖性,这对于广义图像支出至关重要。我们另外提出了U形结构和多视图时间空间预测网络,以增强图像自我重建以及未知的零件预测。我们在实验上证明,我们提出的方法可以为针对最新图像支出方法提供广义图像支出产生可吸引人的结果。
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扩散加权图像(DWIS)中的噪声降低了扩散张量磁共振成像(DTI)导出的微结构参数的准确性和精度,并导致延长的采集时间来实现改进的信噪比(SNR)。基于深度学习的图像去噪使用卷积神经网络(CNNS)具有卓越的性能,但通常需要额外的高SNR数据来监督CNN的培训,这降低了实际可行性。我们开发了一个自我监督的深度学习的方法,标题为“SDNDTI”,用于去噪DTI数据,这不需要额外的高SNR数据进行培训。具体地,SDNDTI将多向DTI数据划分为许多子集,每个子​​集中沿着沿着最佳选择的扩散编码方向组成的六个DWI卷,该编码方向是对张力配件的稳健,然后沿着拟合的扩散张量沿所有获取的方向合成DWI体积使用数据的每个子集作为CNN的输入数据。另一方面,SDNDTI沿着使用所有获取的数据作为训练目标的扩散张量,沿着获取的扩散编码方向合成DWI卷。 SDNDTI使用深3维CNN从合成的DWI卷中的每个子集中消除噪声,以匹配清洁器目标DWI卷的质量,通过平均所有去噪数据的所有子集实现更高的SNR。 SDNDTI的去噪功效在于人类连接项目(HCP)提供的两种数据集和衰老中的寿命HCP。 SDNDTI结果保留了图像清晰度和纹理细节,并大大改善了原始数据的影响。 SDNDTI的结果与来自最先进的传统去噪算法包括BM4D,AONLM和MPPCA的常规去噪算法的结果相当。
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As various city agencies and mobility operators navigate toward innovative mobility solutions, there is a need for strategic flexibility in well-timed investment decisions in the design and timing of mobility service regions, i.e. cast as "real options" (RO). This problem becomes increasingly challenging with multiple interacting RO in such investments. We propose a scalable machine learning based RO framework for multi-period sequential service region design & timing problem for mobility-on-demand services, framed as a Markov decision process with non-stationary stochastic variables. A value function approximation policy from literature uses multi-option least squares Monte Carlo simulation to get a policy value for a set of interdependent investment decisions as deferral options (CR policy). The goal is to determine the optimal selection and timing of a set of zones to include in a service region. However, prior work required explicit enumeration of all possible sequences of investments. To address the combinatorial complexity of such enumeration, we propose a new variant "deep" RO policy using an efficient recurrent neural network (RNN) based ML method (CR-RNN policy) to sample sequences to forego the need for enumeration, making network design & timing policy tractable for large scale implementation. Experiments on multiple service region scenarios in New York City (NYC) shows the proposed policy substantially reduces the overall computational cost (time reduction for RO evaluation of > 90% of total investment sequences is achieved), with zero to near-zero gap compared to the benchmark. A case study of sequential service region design for expansion of MoD services in Brooklyn, NYC show that using the CR-RNN policy to determine optimal RO investment strategy yields a similar performance (0.5% within CR policy value) with significantly reduced computation time (about 5.4 times faster).
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Springs are efficient in storing and returning elastic potential energy but are unable to hold the energy they store in the absence of an external load. Lockable springs use clutches to hold elastic potential energy in the absence of an external load but have not yet been widely adopted in applications, partly because clutches introduce design complexity, reduce energy efficiency, and typically do not afford high-fidelity control over the energy stored by the spring. Here, we present the design of a novel lockable compression spring that uses a small capstan clutch to passively lock a mechanical spring. The capstan clutch can lock up to 1000 N force at any arbitrary deflection, unlock the spring in less than 10 ms with a control force less than 1 % of the maximal spring force, and provide an 80 % energy storage and return efficiency (comparable to a highly efficient electric motor operated at constant nominal speed). By retaining the form factor of a regular spring while providing high-fidelity locking capability even under large spring forces, the proposed design could facilitate the development of energy-efficient spring-based actuators and robots.
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