Graph neural networks (GNNs) find applications in various domains such as computational biology, natural language processing, and computer security. Owing to their popularity, there is an increasing need to explain GNN predictions since GNNs are black-box machine learning models. One way to address this is counterfactual reasoning where the objective is to change the GNN prediction by minimal changes in the input graph. Existing methods for counterfactual explanation of GNNs are limited to instance-specific local reasoning. This approach has two major limitations of not being able to offer global recourse policies and overloading human cognitive ability with too much information. In this work, we study the global explainability of GNNs through global counterfactual reasoning. Specifically, we want to find a small set of representative counterfactual graphs that explains all input graphs. Towards this goal, we propose GCFExplainer, a novel algorithm powered by vertex-reinforced random walks on an edit map of graphs with a greedy summary. Extensive experiments on real graph datasets show that the global explanation from GCFExplainer provides important high-level insights of the model behavior and achieves a 46.9% gain in recourse coverage and a 9.5% reduction in recourse cost compared to the state-of-the-art local counterfactual explainers.
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图表神经网络(GNNS)在行业中,由于各种预测任务的表现令人印象深刻,在行业中获得了显着的采用。然而,单独的性能是不够的。任何广泛部署的机器学习算法都必须强大到对抗性攻击。在这项工作中,我们调查了GNN的这个方面,识别漏洞,并将它们链接到图形属性,可能导致更安全和强大的GNN的开发。具体而言,我们制定任务和模型不可知逃避攻击问题,其中对手修改了测试图以影响任何未知下游任务的性能。提出的算法,盛大($ GR $ APH $ A $ TTACK通过$ N $ eighbors $ D $ Istorration)显示节点邻域的失真在急剧损害预测性能方面是有效的。虽然邻里失真是一个NP难题,但是宏伟设计了通过具有深入$ Q $ -Learning的图形同构网络的新组合的启发式。关于实际数据集的广泛实验表明,平均而言,盛大的速度高达50美元,而不是最先进的技术,同时速度超过100美元。
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子图相似度搜索是图形分析中的基本操作员。在此框架中,给定查询图和图形数据库,目标是识别结构图的数据库图的子图,这些图是与查询相似的。子图编辑距离(SED)是子图相似度最有表现力的措施之一。在这项工作中,我们研究了从训练的图形对和他们的SED值训练SED的问题。为此,我们设计了一种名为Neurosed的新型暹罗图形神经网络,其学习嵌入空间,具有丰富的结构,让人想起SED。借助专门制作的归纳偏差,不仅可以实现高精度,而且确保预测的SED,如真正的SED,满足三角不等式。设计足够通用,也可以模拟图表编辑距离(GED),同时确保预测的GED空间是指标,如真正的GED空间。对于SED和GED的真实图数据集进行了广泛的实验,建立了神经传播的RMSE比现有技术的约2倍,并且比最快的基线快约18倍。此外,由于其对独立的嵌入和理论性质,神经翻转允许大约3个峰值检索图形和子图。
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图形神经网络(GNN),图数据上深度神经网络的概括已被广泛用于各个领域,从药物发现到推荐系统。但是,当可用样本很少的情况下,这些应用程序的GNN是有限的。元学习一直是解决机器学习中缺乏样品的重要框架,近年来,研究人员已经开始将元学习应用于GNNS。在这项工作中,我们提供了对涉及GNN的不同元学习方法的综合调查,这些方法在各种图表中显示出使用这两种方法的力量。我们根据提出的架构,共享表示和应用程序分类文献。最后,我们讨论了几个激动人心的未来研究方向和打开问题。
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The open-radio access network (O-RAN) embraces cloudification and network function virtualization for base-band function processing by dis-aggregated radio units (RUs), distributed units (DUs), and centralized units (CUs). These enable the cloud-RAN vision in full, where multiple mobile network operators (MNOs) can install their proprietary or open RUs, but lease on-demand computational resources for DU-CU functions from commonly available open-clouds via open x-haul interfaces. In this paper, we propose and compare the performances of min-max fairness and Vickrey-Clarke-Groves (VCG) auction-based x-haul and DU-CU resource allocation mechanisms to create a multi-tenant O-RAN ecosystem that is sustainable for small, medium, and large MNOs. The min-max fair approach minimizes the maximum OPEX of RUs through cost-sharing proportional to their demands, whereas the VCG auction-based approach minimizes the total OPEX for all resources utilized while extracting truthful demands from RUs. We consider time-wavelength division multiplexed (TWDM) passive optical network (PON)-based x-haul interfaces where PON virtualization technique is used to flexibly provide optical connections among RUs and edge-clouds at macro-cell RU locations as well as open-clouds at the central office locations. Moreover, we design efficient heuristics that yield significantly better economic efficiency and network resource utilization than conventional greedy resource allocation algorithms and reinforcement learning-based algorithms.
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Deep Learning and Machine Learning based models have become extremely popular in text processing and information retrieval. However, the non-linear structures present inside the networks make these models largely inscrutable. A significant body of research has focused on increasing the transparency of these models. This article provides a broad overview of research on the explainability and interpretability of natural language processing and information retrieval methods. More specifically, we survey approaches that have been applied to explain word embeddings, sequence modeling, attention modules, transformers, BERT, and document ranking. The concluding section suggests some possible directions for future research on this topic.
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Recent advances in operator learning theory have improved our knowledge about learning maps between infinite dimensional spaces. However, for large-scale engineering problems such as concurrent multiscale simulation for mechanical properties, the training cost for the current operator learning methods is very high. The article presents a thorough analysis on the mathematical underpinnings of the operator learning paradigm and proposes a kernel learning method that maps between function spaces. We first provide a survey of modern kernel and operator learning theory, as well as discuss recent results and open problems. From there, the article presents an algorithm to how we can analytically approximate the piecewise constant functions on R for operator learning. This implies the potential feasibility of success of neural operators on clustered functions. Finally, a k-means clustered domain on the basis of a mechanistic response is considered and the Lippmann-Schwinger equation for micro-mechanical homogenization is solved. The article briefly discusses the mathematics of previous kernel learning methods and some preliminary results with those methods. The proposed kernel operator learning method uses graph kernel networks to come up with a mechanistic reduced order method for multiscale homogenization.
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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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This paper surveys some recent developments in measures of association related to a new coefficient of correlation introduced by the author. A straightforward extension of this coefficient to standard Borel spaces (which includes all Polish spaces), overlooked in the literature so far, is proposed at the end of the survey.
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Aspect Based Sentiment Analysis is a dominant research area with potential applications in social media analytics, business, finance, and health. Prior works in this area are primarily based on supervised methods, with a few techniques using weak supervision limited to predicting a single aspect category per review sentence. In this paper, we present an extremely weakly supervised multi-label Aspect Category Sentiment Analysis framework which does not use any labelled data. We only rely on a single word per class as an initial indicative information. We further propose an automatic word selection technique to choose these seed categories and sentiment words. We explore unsupervised language model post-training to improve the overall performance, and propose a multi-label generator model to generate multiple aspect category-sentiment pairs per review sentence. Experiments conducted on four benchmark datasets showcase our method to outperform other weakly supervised baselines by a significant margin.
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