Structure-based drug design (SBDD) aims to discover drug candidates by finding molecules (ligands) that bind tightly to a disease-related protein (targets), which is the primary approach to computer-aided drug discovery. Recently, applying deep generative models for three-dimensional (3D) molecular design conditioned on protein pockets to solve SBDD has attracted much attention, but their formulation as probabilistic modeling often leads to unsatisfactory optimization performance. On the other hand, traditional combinatorial optimization methods such as genetic algorithms (GA) have demonstrated state-of-the-art performance in various molecular optimization tasks. However, they do not utilize protein target structure to inform design steps but rely on a random-walk-like exploration, which leads to unstable performance and no knowledge transfer between different tasks despite the similar binding physics. To achieve a more stable and efficient SBDD, we propose Reinforced Genetic Algorithm (RGA) that uses neural models to prioritize the profitable design steps and suppress random-walk behavior. The neural models take the 3D structure of the targets and ligands as inputs and are pre-trained using native complex structures to utilize the knowledge of the shared binding physics from different targets and then fine-tuned during optimization. We conduct thorough empirical studies on optimizing binding affinity to various disease targets and show that RGA outperforms the baselines in terms of docking scores and is more robust to random initializations. The ablation study also indicates that the training on different targets helps improve performance by leveraging the shared underlying physics of the binding processes. The code is available at https://github.com/futianfan/reinforced-genetic-algorithm.
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In deep neural networks (DNNs), there are a huge number of weights and multiply-and-accumulate (MAC) operations. Accordingly, it is challenging to apply DNNs on resource-constrained platforms, e.g., mobile phones. Quantization is a method to reduce the size and the computational complexity of DNNs. Existing quantization methods either require hardware overhead to achieve a non-uniform quantization or focus on model-wise and layer-wise uniform quantization, which are not as fine-grained as filter-wise quantization. In this paper, we propose a class-based quantization method to determine the minimum number of quantization bits for each filter or neuron in DNNs individually. In the proposed method, the importance score of each filter or neuron with respect to the number of classes in the dataset is first evaluated. The larger the score is, the more important the filter or neuron is and thus the larger the number of quantization bits should be. Afterwards, a search algorithm is adopted to exploit the different importance of filters and neurons to determine the number of quantization bits of each filter or neuron. Experimental results demonstrate that the proposed method can maintain the inference accuracy with low bit-width quantization. Given the same number of quantization bits, the proposed method can also achieve a better inference accuracy than the existing methods.
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Deep neural networks (DNNs) have successfully been applied in many fields in the past decades. However, the increasing number of multiply-and-accumulate (MAC) operations in DNNs prevents their application in resource-constrained and resource-varying platforms, e.g., mobile phones and autonomous vehicles. In such platforms, neural networks need to provide acceptable results quickly and the accuracy of the results should be able to be enhanced dynamically according to the computational resources available in the computing system. To address these challenges, we propose a design framework called SteppingNet. SteppingNet constructs a series of subnets whose accuracy is incrementally enhanced as more MAC operations become available. Therefore, this design allows a trade-off between accuracy and latency. In addition, the larger subnets in SteppingNet are built upon smaller subnets, so that the results of the latter can directly be reused in the former without recomputation. This property allows SteppingNet to decide on-the-fly whether to enhance the inference accuracy by executing further MAC operations. Experimental results demonstrate that SteppingNet provides an effective incremental accuracy improvement and its inference accuracy consistently outperforms the state-of-the-art work under the same limit of computational resources.
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强化学习(RL)和连续的非线性控制已成功部署在复杂的顺序决策任务的多个领域中。但是,鉴于学习过程的探索性质和模型不确定性的存在,由于缺乏安全保证,将它们应用于安全至关重要的控制任务是一项挑战。另一方面,尽管将控制理论方法与学习算法相结合,但在安全RL应用中显示了希望,但安全数据收集过程的样本效率尚未得到很好的解决。在本文中,我们提出了一个\ emph {可证明的}示例有效的情节安全学习框架,用于在线控制任务,以利用未知的非线性动力学系统来利用安全的探索和剥削。特别是,框架1)在随机设置中扩展控制屏障功能(CBF),以在模型学习过程中实现可证明的高概率安全性,2)整合基于乐观的探索策略,以有效地将安全探索过程与学习的动态有效地指导安全探索过程对于\ emph {接近最佳}控制性能。我们对与理论保证的最佳控制器和概率安全性的偶发性遗憾进行了正式分析。提供了仿真结果以证明所提出算法的有效性和效率。
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产品检索在电子商务领域非常重要。本文介绍了我们在eBay Eproduct Visual Search Challenge(FGVC9)中介绍的第一个解决方案,该解决方案是来自视觉模型和视觉模型的大约20个模型的集合。尽管模型合奏很普遍,但我们表明,将视觉模型和视觉模型结合起来带来了特殊的互补性,这是我们优越性的关键因素。具体而言,对于视觉模型,我们使用两阶段的训练管道,该管道首先从训练集中提供的粗制标签中学习,然后进行细粒度的自学训练,从而产生粗到5的度量度量学习方式。对于视觉语言模型,我们将训练图像的文本描述用作微调图像编码器(功能提取器)的监督信号。通过这些设计,我们的解决方案达到了0.7623 Mar@10,在所有竞争对手中排名第一。该代码可在:\ href {https://github.com/wangwenhao0716/v2l} {v $^2 $ l}中获得。
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在过去的几年中,在各种文本生成任务中见证了各种自动编码器的优势。但是,由于文本的顺序性质,自动回归解码器倾向于忽略潜在变量,然后降低到简单的语言模型,称为KL消失的问题,当VAE与基于变压器的结构结合时,这将进一步恶化。为了改善这个问题,我们提出了一种新型变化变压器框架Della。德拉(Della)从较低层的层中得知一系列层的潜在变量,每个变量都从下层的层中推断出,并通过低级张量产品与隐藏状态紧密耦合。通过这种方式,Della强迫这些后部潜在变量将其与整个计算路径深入融合,从而结合了更多信息。从理论上讲,我们可以将我们的方法视为纠缠潜在变量,以避免通过层减少后验信息,从而使DELLA即使没有任何退火或阈值技巧,也可以使DELLA获得更高的非零KL值。与多个强大的基线相比,对四个无条件和三个条件生成任务的实验表明,Della可以更好地减轻KL消失并改善质量和多样性。
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在本文中,我们研究了部分可观察到的动态系统的在线增强学习(RL)。我们专注于预测状态表示(PSRS)模型,该模型是捕获其他知名模型(例如可观察到的马尔可夫决策过程(POMDP))的表达模型。 PSR使用一组未来观察结果的预测表示状态,并完全使用可观察的数量来定义。我们为PSRS开发了一种新型的基于模型的算法,该算法可以在样本复杂性中学习相对于系统的所有相关参数的多项式缩放的近乎最佳策略。我们的算法自然可以与功能近似合作,以扩展到具有较大状态和观察空间的系统。我们表明,给定一个可实现的模型类别,学习近乎最佳策略的样本复杂性仅相对于模型类的统计复杂性,而没有任何明确的多项式依赖性对状态和观察空间的大小依赖。值得注意的是,我们的工作是表明多项式样本复杂性与PSR中全球最佳政策竞争的第一项工作。最后,我们演示了如何直接使用我们的一般定理来得出特殊模型的样本复杂性界限,包括$ m $ $ step弱揭示和$ m $ $ $ - 可解码的表格pomdps,具有低率潜在过渡的POMDP和具有线性pomdps的POMDP排放和潜在过渡。
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从任务不足的预训练的深层模型中转移知识以进行下游任务是计算机视觉研究中的一个重要主题。随着计算能力的增长,我们现在拥有大规模的模型体系结构和数据量的开源视觉语言预培训模型。在这项研究中,我们专注于转移视力分类任务的知识。传统方法随机初始化线性分类器头进行视觉分类,但是它们将文本编码器的用法留为未发现的下游视觉识别任务。在本文中,我们修改了线性分类器的角色,并用对象类别的嵌入式语言表示替换分类器。这些语言表示是从视觉语言预训练模型的文本编码器初始化的,以进一步利用其良好的语言模型参数。实证研究表明,我们的方法提高了视频分类的性能和训练速度,模型的变化微不足道。特别是,我们的范式在动力学400上实现了87.3%的最新准确性。
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图像复制检测(ICD)旨在确定查询图像是否是参考集中的任何图像的编辑副本。当前,ICD的公共基准非常有限,而在现实世界中,遍布整个关键的挑战,即分散了严格的负面查询。具体而言,某些查询不是编辑的副本,而是与某些参考图像的本质相似。这些硬负查询很容易被错误地识别为已编辑的副本,从而显着损害了ICD的精度。这种观察激发了我们建立以这种特征为特征的第一个ICD基准。基于现有的ICD数据集,本文通过分别在培训和测试集中添加100、000和24、252硬负对来构建新数据集。此外,本文进一步揭示了解决ICD中严重负面问题的独特困难,即当前的度量学习与ICD之间存在根本的冲突。这场冲突是:公制学习采用对称距离,而编辑的副本是不对称的(单向)过程,例如,部分作物接近其整体参考图像,并且是编辑的副本,而后者则不能是编辑的副本。以前(尽管距离同样小)。这种洞察力导致不对称的相似性学习(ASL)方法,该方法允许在两个方向上的相似性(查询<->参考图像)彼此不同。实验结果表明,ASL通过明确的边缘胜过最先进的方法,证实解决对称性 - 对称冲突对于ICD至关重要。
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实现通用语言情报是自然语言处理的长期目标,标准评估基准发挥基本和指导作用。我们认为,对于通用语言智能评估,基准本身需要全面和系统。为此,我们提出了Cuge,一种中文语言理解和生成评估基准,具有以下特征:(1)分层基准框架,其中数据集主要选择和组织语言能力 - 任务数据集层次结构。 (2)多级评分策略,其中基于分层框架提供了不同级别的模型性能。为了促进CUGE,我们提供了一个公共排行榜,可以自定义,以支持灵活的模型判断标准。代表性预先训练的语言模型的评估结果表明了对通用语言智能的完善的充足空间。 Cuge在Cuge.baai.ac.cn上公开提供。
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