We investigate ensemble methods for prediction in an online setting. Unlike all the literature in ensembling, for the first time, we introduce a new approach using a meta learner that effectively combines the base model predictions via using a superset of the features that is the union of the base models' feature vectors instead of the predictions themselves. Here, our model does not use the predictions of the base models as inputs to a machine learning algorithm, but choose the best possible combination at each time step based on the state of the problem. We explore three different constraint spaces for the ensembling of the base learners that linearly combines the base predictions, which are convex combinations where the components of the ensembling vector are all nonnegative and sum up to 1; affine combinations where the weight vector components are required to sum up to 1; and the unconstrained combinations where the components are free to take any real value. The constraints are both theoretically analyzed under known statistics and integrated into the learning procedure of the meta learner as a part of the optimization in an automated manner. To show the practical efficiency of the proposed method, we employ a gradient-boosted decision tree and a multi-layer perceptron separately as the meta learners. Our framework is generic so that one can use other machine learning architectures as the ensembler as long as they allow for a custom differentiable loss for minimization. We demonstrate the learning behavior of our algorithm on synthetic data and the significant performance improvements over the conventional methods over various real life datasets, extensively used in the well-known data competitions. Furthermore, we openly share the source code of the proposed method to facilitate further research and comparison.

串联连接的机器人是希望在大规模灾害中的搜索和救援等限制空间中执行任务的候选人。这种机器人通常是韧带，我们假设肢体的添加可以改善移动性。然而，在设计和控制这种装置方面的挑战在于以提高移动性的方式协调高维冗余模块。在这里，我们开发了一个控制串联连接的多腿机器人的一般框架。具体地，我们结合了两种方法来构建一般的形状控制方案，其可以为各种机器人形态的有效运动提供自变形（“Gaits”）的基线模式。首先，我们从维度降低和生物步态分类方案中获取灵感，以产生身体变形和脚提升/降低的循环模式，其促进了任意基板接触图案的产生。其次，我们使用几何力学方法来促进识别这些起伏的最佳相位，以最大化速度和/或稳定性。我们的方案允许在扁平摩擦地形上的多腿机器人机车上的有效Gaits开发有多种数量的四肢（4,6,16，甚至0四肢）和身体致动能力（包括在Limbless设备上的侧壁Gaits）。通过适当协调身体波动和腿部放置，我们的框架结合了Limbless机器人（模块化）和腿机器人（移动性）的优势。我们预计我们的框架可以提供一般的控制方案，以便快速部署一般的多腿机器人，铺平往达在现实条件下遍历复杂环境的机器的方式。

Adversarial training has been empirically shown to be more prone to overfitting than standard training. The exact underlying reasons still need to be fully understood. In this paper, we identify one cause of overfitting related to current practices of generating adversarial samples from misclassified samples. To address this, we propose an alternative approach that leverages the misclassified samples to mitigate the overfitting problem. We show that our approach achieves better generalization while having comparable robustness to state-of-the-art adversarial training methods on a wide range of computer vision, natural language processing, and tabular tasks.

Adversarial training is widely acknowledged as the most effective defense against adversarial attacks. However, it is also well established that achieving both robustness and generalization in adversarially trained models involves a trade-off. The goal of this work is to provide an in depth comparison of different approaches for adversarial training in language models. Specifically, we study the effect of pre-training data augmentation as well as training time input perturbations vs. embedding space perturbations on the robustness and generalization of BERT-like language models. Our findings suggest that better robustness can be achieved by pre-training data augmentation or by training with input space perturbation. However, training with embedding space perturbation significantly improves generalization. A linguistic correlation analysis of neurons of the learned models reveal that the improved generalization is due to `more specialized' neurons. To the best of our knowledge, this is the first work to carry out a deep qualitative analysis of different methods of generating adversarial examples in adversarial training of language models.

Automatic keyword extraction (AKE) has gained more importance with the increasing amount of digital textual data that modern computing systems process. It has various applications in information retrieval (IR) and natural language processing (NLP), including text summarisation, topic analysis and document indexing. This paper proposes a simple but effective post-processing-based universal approach to improve the performance of any AKE methods, via an enhanced level of semantic-awareness supported by PoS-tagging. To demonstrate the performance of the proposed approach, we considered word types retrieved from a PoS-tagging step and two representative sources of semantic information -- specialised terms defined in one or more context-dependent thesauri, and named entities in Wikipedia. The above three steps can be simply added to the end of any AKE methods as part of a post-processor, which simply re-evaluate all candidate keywords following some context-specific and semantic-aware criteria. For five state-of-the-art (SOTA) AKE methods, our experimental results with 17 selected datasets showed that the proposed approach improved their performances both consistently (up to 100\% in terms of improved cases) and significantly (between 10.2\% and 53.8\%, with an average of 25.8\%, in terms of F1-score and across all five methods), especially when all the three enhancement steps are used. Our results have profound implications considering the ease to apply our proposed approach to any AKE methods and to further extend it.

The horseshoe prior is known to possess many desirable properties for Bayesian estimation of sparse parameter vectors, yet its density function lacks an analytic form. As such, it is challenging to find a closed-form solution for the posterior mode. Conventional horseshoe estimators use the posterior mean to estimate the parameters, but these estimates are not sparse. We propose a novel expectation-maximisation (EM) procedure for computing the MAP estimates of the parameters in the case of the standard linear model. A particular strength of our approach is that the M-step depends only on the form of the prior and it is independent of the form of the likelihood. We introduce several simple modifications of this EM procedure that allow for straightforward extension to generalised linear models. In experiments performed on simulated and real data, our approach performs comparable, or superior to, state-of-the-art sparse estimation methods in terms of statistical performance and computational cost.

We propose a) a Language Agnostic end-to-end Speech Translation model (LAST), and b) a data augmentation strategy to increase code-switching (CS) performance. With increasing globalization, multiple languages are increasingly used interchangeably during fluent speech. Such CS complicates traditional speech recognition and translation, as we must recognize which language was spoken first and then apply a language-dependent recognizer and subsequent translation component to generate the desired target language output. Such a pipeline introduces latency and errors. In this paper, we eliminate the need for that, by treating speech recognition and translation as one unified end-to-end speech translation problem. By training LAST with both input languages, we decode speech into one target language, regardless of the input language. LAST delivers comparable recognition and speech translation accuracy in monolingual usage, while reducing latency and error rate considerably when CS is observed.

深度度量学习（DML）旨在最大程度地减少嵌入图像中成对内部/间阶层接近性违规的经验预期损失。我们将DML与有限机会限制的可行性问题联系起来。我们表明，基于代理的DML的最小化器满足了某些机会限制，并且基于代理方法的最坏情况可以通过围绕类代理的最小球的半径来表征，以覆盖相应类的整个域样本，建议每课多个代理有助于表现。为了提供可扩展的算法并利用更多代理，我们考虑了基于代理的DML实例的最小化者所隐含的机会限制，并将DML重新制定为在此类约束的交叉点中找到可行的点，从而导致问题近似解决。迭代预测。简而言之，我们反复训练基于代理的损失，并用故意选择的新样本的嵌入来重新定位代理。我们将我们的方法应用于公认的损失，并在四个流行的基准数据集上评估图像检索。优于最先进的方法，我们的方法一致地提高了应用损失的性能。代码可在以下网址找到：https：//github.com/yetigurbuz/ccp-dml

探索搜索空间是几十年来吸引研究人员兴趣的最不可预测的挑战之一。处理不可预测性的一种方法是表征搜索空间并采取相应的行动。特征良好的搜索空间可以帮助将问题状态映射到一组运算符，以生成新的问题状态。在本文中，已经使用最知名的机器学习方法分析了基于景观分析的功能集，以确定最佳功能集。但是，为了处理问题的复杂性并引起共同点以跨领域转移经验，最具代表性特征的选择仍然至关重要。提出的方法分析了一组特征的预测性，以确定最佳分类。

从学术文章中自动提取资金信息为行业和研究社区增添了重要价值，例如基于收到的资金进行资助组织，研究人员和大学的研究成果，并支持开放访问政策。识别和链接资金实体的两个主要挑战是：（i）知识库（KB）的稀疏图结构，这使得基于图的常用实体链接方法的资金域链接方法，（ii）KB中的缺失实体，这（与最近的零拍方法不同）需要标记实体提及没有KB条目为零。我们提出了一个可以执行零预测并克服数据稀缺问题的实体链接模型。我们的模型建立在基于变压器的提及检测和双重编码模型的基础上，以执行实体链接。我们表明，我们的模型表现优于现有基线。