放射造影通常用于探测动态系统中的复杂,不断发展的密度字段,以便在潜在的物理学中实现进入洞察力。该技术已用于许多领域,包括材料科学,休克物理,惯性监禁融合和其他国家安全应用。然而,在许多这些应用中,噪声,散射,复杂光束动力学等的并发症防止了密度的重建足以足以识别具有足够置信度的底层物理。因此,来自静态/动态射线照相的密度重建通常限于在许多这些应用中识别诸如裂缝和空隙的不连续特征。在这项工作中,我们提出了一种从基本上重建密度的基本上新的射线照片序列的密度。仅使用射线照相识别的稳健特征,我们将它们与使用机器学习方法的底层流体动力方程组合,即条件生成对冲网络(CGAN),以从射线照片的动态序列确定密度字段。接下来,我们寻求通过参数估计和投影的过程进一步提高ML的密度重建的流体动力学一致性,并进入流体动力歧管。在这种情况下,我们注意到,训练数据给出的流体动力歧管在被认为的参数空间中给出的测试数据是用于预测的稳定性的诊断,并用于增强培训数据库,期望后者将进一步降低未来的密度重建错误。最后,我们展示了这种方法优于传统的射线照相重建在捕获允许的流体动力学路径中的能力,即使存在相对少量的散射。
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Correct scoring of a driver's risk is of great significance to auto insurance companies. While the current tools used in this field have been proven in practice to be quite efficient and beneficial, we argue that there is still a lot of room for development and improvement in the auto insurance risk estimation process. To this end, we develop a framework based on a combination of a neural network together with a dimensionality reduction technique t-SNE (t-distributed stochastic neighbour embedding). This enables us to visually represent the complex structure of the risk as a two-dimensional surface, while still preserving the properties of the local region in the features space. The obtained results, which are based on real insurance data, reveal a clear contrast between the high and low risk policy holders, and indeed improve upon the actual risk estimation performed by the insurer. Due to the visual accessibility of the portfolio in this approach, we argue that this framework could be advantageous to the auto insurer, both as a main risk prediction tool and as an additional validation stage in other approaches.
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$ $With recent advances in CNNs, exceptional improvements have been made in semantic segmentation of high resolution images in terms of accuracy and latency. However, challenges still remain in detecting objects in crowded scenes, large scale variations, partial occlusion, and distortions, while still maintaining mobility and latency. We introduce a fast and efficient convolutional neural network, ASBU-Net, for semantic segmentation of high resolution images that addresses these problems and uses no novelty layers for ease of quantization and embedded hardware support. ASBU-Net is based on a new feature extraction module, atrous space bender layer (ASBL), which is efficient in terms of computation and memory. The ASB layers form a building block that is used to make ASBNet. Since this network does not use any special layers it can be easily implemented, quantized and deployed on FPGAs and other hardware with limited memory. We present experiments on resource and accuracy trade-offs and show strong performance compared to other popular models.
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MD4 and MD5 are seminal cryptographic hash functions proposed in early 1990s. MD4 consists of 48 steps and produces a 128-bit hash given a message of arbitrary finite size. MD5 is a more secure 64-step extension of MD4. Both MD4 and MD5 are vulnerable to practical collision attacks, yet it is still not realistic to invert them, i.e. to find a message given a hash. In 2007, the 39-step version of MD4 was inverted via reducing to SAT and applying a CDCL solver along with the so-called Dobbertin's constraints. As for MD5, in 2012 its 28-step version was inverted via a CDCL solver for one specified hash without adding any additional constraints. In this study, Cube-and-Conquer (a combination of CDCL and lookahead) is applied to invert step-reduced versions of MD4 and MD5. For this purpose, two algorithms are proposed. The first one generates inversion problems for MD4 by gradually modifying the Dobbertin's constraints. The second algorithm tries the cubing phase of Cube-and-Conquer with different cutoff thresholds to find the one with minimal runtime estimation of the conquer phase. This algorithm operates in two modes: (i) estimating the hardness of an arbitrary given formula; (ii) incomplete SAT-solving of a given satisfiable formula. While the first algorithm is focused on inverting step-reduced MD4, the second one is not area-specific and so is applicable to a variety of classes of hard SAT instances. In this study, for the first time in history, 40-, 41-, 42-, and 43-step MD4 are inverted via the first algorithm and the estimating mode of the second algorithm. 28-step MD5 is inverted for four hashes via the incomplete SAT-solving mode of the second algorithm. For three hashes out of them this is done for the first time.
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Accurate mapping of forests is critical for forest management and carbon stocks monitoring. Deep learning is becoming more popular in Earth Observation (EO), however, the availability of reference data limits its potential in wide-area forest mapping. To overcome those limitations, here we introduce contrastive regression into EO based forest mapping and develop a novel semisupervised regression framework for wall-to-wall mapping of continuous forest variables. It combines supervised contrastive regression loss and semi-supervised Cross-Pseudo Regression loss. The framework is demonstrated over a boreal forest site using Copernicus Sentinel-1 and Sentinel-2 imagery for mapping forest tree height. Achieved prediction accuracies are strongly better compared to using vanilla UNet or traditional regression models, with relative RMSE of 15.1% on stand level. We expect that developed framework can be used for modeling other forest variables and EO datasets.
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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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自动临床标题生成问题被称为建议模型,将额叶X射线扫描与放射学记录中的结构化患者信息结合在一起。我们将两种语言模型结合在一起,即表演 - 泰尔和GPT-3,以生成全面和描述性的放射学记录。这些模型的建议组合产生了文本摘要,其中包含有关发现的病理,其位置以及将每个病理定位在原始X射线扫描中的每个病理的2D热图。提出的模型在两个医学数据集(Open-I,Mimic-CXR和通用MS-Coco)上进行了测试。用自然语言评估指标测量的结果证明了它们对胸部X射线图像字幕的有效适用性。
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大多数从功能磁共振成像(fMRI)数据估算大脑功能连接性的方法依赖于计算统计依赖性的某些度量,或者更一般地,单变量代表性的时间序列(ROIS)(ROI)由多个Voxels组成。但是,总结ROI的多个时间序列具有其平均值或第一个主成分(1pc)可能导致信息丢失,例如,1PC仅解释了神经元活动的多变量信号的一小部分。我们建议在不使用代表性时间序列的情况下直接比较ROI,并根据Wasserstein距离定义了ROI之间的新的多元连通性量度,不一定由相同数量的体素组成。我们在自闭症筛查任务上评估了拟议的Wasserstein功能连接度量,证明了其优越性优于常用单变量和多元功能连通性测量。
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使用高斯混合模型(GMM)的变异推断能够学习可侵入性目标分布的高度扣除但多模式的近似值。 GMM与最多数百个维度的问题设置特别相关,例如机器人技术,用于对轨迹或联合分布进行建模。这项工作着重于基于GMM的两种非常有效的方法,这些方法既采用独立的自然梯度更新来为单个组件和权重的分类分布。我们首次表明,尽管它们的实际实现和理论保证有所不同,但他们的派生更新是等效的。我们确定了几种设计选择,可以区分两种方法,即在样本选择,自然梯度估计,步骤适应以及信任区域是否得到强制或适应的组件数量方面。我们对这些设计选择进行广泛的消融,并表明它们强烈影响了优化的效率和学习分布的可变性。基于我们的见解,我们提出了对广义框架的新颖实例化,该实例将一阶自然梯度估计与信任区域和组件适应相结合,并且在我们所有实验中都显着优于以前的两种方法。
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自2016年成立以来,Alexa奖计划使数百名大学生能够通过Socialbot Grand Challenge探索和竞争以发展对话代理商。挑战的目的是建立能够与人类在流行主题上连贯而诱人的代理人20分钟,同时达到至少4.0/5.0的平均评分。但是,由于对话代理商试图帮助用户完成日益复杂的任务,因此需要新的对话AI技术和评估平台。成立于2021年的Alexa奖Taskbot Challenge建立在Socialbot Challenge的成功基础上,通过引入交互式协助人类进行现实世界烹饪和做自己动手做的任务的要求,同时同时使用语音和视觉方式。这项挑战要求TaskBots识别和理解用户的需求,识别和集成任务和域知识,并开发新的方式,不分散用户的注意力,而不必分散他们的任务,以及其他挑战。本文概述了Taskbot挑战赛,描述了使用Cobot Toolkit提供给团队提供的基础架构支持,并总结了参与团队以克服研究挑战所采取的方法。最后,它分析了比赛第一年的竞争任务机器人的性能。
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