The spectacular successes of recurrent neural network models where key parameters are adjusted via backpropagation-based gradient descent have inspired much thought as to how biological neuronal networks might solve the corresponding synaptic credit assignment problem. There is so far little agreement, however, as to how biological networks could implement the necessary backpropagation through time, given widely recognized constraints of biological synaptic network signaling architectures. Here, we propose that extra-synaptic diffusion of local neuromodulators such as neuropeptides may afford an effective mode of backpropagation lying within the bounds of biological plausibility. Going beyond existing temporal truncation-based gradient approximations, our approximate gradient-based update rule, ModProp, propagates credit information through arbitrary time steps. ModProp suggests that modulatory signals can act on receiving cells by convolving their eligibility traces via causal, time-invariant and synapse-type-specific filter taps. Our mathematical analysis of ModProp learning, together with simulation results on benchmark temporal tasks, demonstrate the advantage of ModProp over existing biologically-plausible temporal credit assignment rules. These results suggest a potential neuronal mechanism for signaling credit information related to recurrent interactions over a longer time horizon. Finally, we derive an in-silico implementation of ModProp that could serve as a low-complexity and causal alternative to backpropagation through time.

The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.

The orthogonality constraints, including the hard and soft ones, have been used to normalize the weight matrices of Deep Neural Network (DNN) models, especially the Convolutional Neural Network (CNN) and Vision Transformer (ViT), to reduce model parameter redundancy and improve training stability. However, the robustness to noisy data of these models with constraints is not always satisfactory. In this work, we propose a novel two-stage approximately orthogonal training framework (TAOTF) to find a trade-off between the orthogonal solution space and the main task solution space to solve this problem in noisy data scenarios. In the first stage, we propose a novel algorithm called polar decomposition-based orthogonal initialization (PDOI) to find a good initialization for the orthogonal optimization. In the second stage, unlike other existing methods, we apply soft orthogonal constraints for all layers of DNN model. We evaluate the proposed model-agnostic framework both on the natural image and medical image datasets, which show that our method achieves stable and superior performances to existing methods.

The rapid development of aspect-based sentiment analysis (ABSA) within recent decades shows great potential for real-world society. The current ABSA works, however, are mostly limited to the scenario of a single text piece, leaving the study in dialogue contexts unexplored. In this work, we introduce a novel task of conversational aspect-based sentiment quadruple analysis, namely DiaASQ, aiming to detect the sentiment quadruple of target-aspect-opinion-sentiment in a dialogue. DiaASQ bridges the gap between fine-grained sentiment analysis and conversational opinion mining. We manually construct a large-scale, high-quality Chinese dataset and also obtain the English version dataset via manual translation. We deliberately propose a neural model to benchmark the task. It advances in effectively performing end-to-end quadruple prediction and manages to incorporate rich dialogue-specific and discourse feature representations for better cross-utterance quadruple extraction. We finally point out several potential future works to facilitate the follow-up research of this new task. The DiaASQ data is open at https://github.com/unikcc/DiaASQ

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.

We study discrete distribution estimation under user-level local differential privacy (LDP). In user-level $\varepsilon$-LDP, each user has $m\ge1$ samples and the privacy of all $m$ samples must be preserved simultaneously. We resolve the following dilemma: While on the one hand having more samples per user should provide more information about the underlying distribution, on the other hand, guaranteeing the privacy of all $m$ samples should make the estimation task more difficult. We obtain tight bounds for this problem under almost all parameter regimes. Perhaps surprisingly, we show that in suitable parameter regimes, having $m$ samples per user is equivalent to having $m$ times more users, each with only one sample. Our results demonstrate interesting phase transitions for $m$ and the privacy parameter $\varepsilon$ in the estimation risk. Finally, connecting with recent results on shuffled DP, we show that combined with random shuffling, our algorithm leads to optimal error guarantees (up to logarithmic factors) under the central model of user-level DP in certain parameter regimes. We provide several simulations to verify our theoretical findings.

本文提出了一种使用信息理论成本来学习有效地标本地化和探索的连续控制政策的方法。我们考虑一个移动机器人在有限的传感范围内检测地标，并解决学习控制政策的问题，该控制政策最大程度地提高了地标状态与传感器观察之间的相互信息。我们采用Kalman过滤器将地标州的部分可观察到的问题转换为马尔可夫决策过程（MDP），这是一个可区分的视野来塑造奖励，以及基于注意力的神经网络来代表控制策略。除了具有里程碑意义的定位外，该方法通过主动容积映射进一步统一，以促进勘探。与基准方法相比，在几个模拟地标本地化任务中证明了该性能。

多标签遥感图像分类（MLRSIC）已获得越来越多的研究兴趣。将多个标签的辅助关系作为其他信息有助于提高此任务的性能。当前方法着重于使用它来限制卷积神经网络（CNN）的最终功能输出。一方面，这些方法不会充分利用标签相关来形成特征表示。另一方面，它们增加了系统的标签噪声灵敏度，导致稳健性差。在本文中，提出了一种称为语义交织的全球通道注意（Signa）的新颖方法。首先，根据数据集的统计信息获得标签共发生图。标签共发生图用作图形神经网络（GNN）的输入，以生成最佳特征表示。然后，语义特征和视觉特征交错，以指导图像从原始特征空间到具有嵌入式标签关系的语义特征空间的特征表达。 Signa在新的语义特征空间中触发了特征地图通道的全球关注，以提取更重要的视觉特征。提出了基于多头签名的功能自适应加权网络，以插件的方式对任何CNN作用。对于遥感图像，可以通过将CNN插入浅层层来实现更好的分类性能。我们对三个数据集进行了广泛的实验比较：UCM数据集，AID数据集和DFC15数据集。实验结果表明，与最新方法（SOTA）方法相比，所提出的Signa具有出色的分类性能。值得一提的是，本文的代码将向社区开放，以进行可重复性研究。我们的代码可在https://github.com/kyle-one/signa上找到。

由于规模和形状的极端复杂性以及预测位置的不确定性，光学遥感图像（RSI-SOD）中的显着对象检测是一项非常困难的任务。现有的SOD方法可以满足自然场景图像的检测性能，但是由于遥感图像中上述图像特性，它们不能很好地适应RSI-SOD。在本文中，我们为光学RSIS中的SOD提出了一个新颖的注意力指导网络（AGNET），包括位置增强阶段和细节细节阶段。具体而言，位置增强阶段由语义注意模块和上下文注意模块组成，以准确描述显着对象的大致位置。细节完善阶段使用提出的自我注册模块在注意力的指导下逐步完善预测结果并逆转注意力。此外，混合损失用于监督网络的培训，这可以从像素，区域和统计数据的三个角度来改善模型的性能。在两个流行的基准上进行的广泛实验表明，与其他最先进的方法相比，AGNET可以达到竞争性能。该代码将在https://github.com/nuaayh/agnet上找到。

现实世界中的应用程序需要在物理世界中运行的机器人，除了完成任务外，还要意识到潜在风险。大部分危险行为是由于与负担无知的物体相互作用而产生的。为了防止代理做出不安全的决定，我们建议通过强化学习来训练机器人代理，以了解对室内环境中质量和摩擦等物理特性的任务。我们通过一种新颖的物理启发奖励功能来实现这一目标，该功能鼓励代理商学习辨别不同质量和摩擦系数的政策。我们介绍了两项新颖且具有挑战性的室内重排任务 - 可变的摩擦推动任务和可变的质量推动任务 - 允许评估学习绩效和物理启发的风险时学到的政策。我们的结果表明，通过配备拟议的奖励，代理商能够学习选择推动目标或目标轨迹的政策，以最低的身体成本，可以进一步利用这一预防措施来限制代理商在安全性批评中的行为环境。