Individual-level data (microdata) that characterizes a population, is essential for studying many real-world problems. However, acquiring such data is not straightforward due to cost and privacy constraints, and access is often limited to aggregated data (macro data) sources. In this study, we examine synthetic data generation as a tool to extrapolate difficult-to-obtain high-resolution data by combining information from multiple easier-to-obtain lower-resolution data sources. In particular, we introduce a framework that uses a combination of univariate and multivariate frequency tables from a given target geographical location in combination with frequency tables from other auxiliary locations to generate synthetic microdata for individuals in the target location. Our method combines the estimation of a dependency graph and conditional probabilities from the target location with the use of a Gaussian copula to leverage the available information from the auxiliary locations. We perform extensive testing on two real-world datasets and demonstrate that our approach outperforms prior approaches in preserving the overall dependency structure of the data while also satisfying the constraints defined on the different variables.

In recent years, several metrics have been developed for evaluating group fairness of rankings. Given that these metrics were developed with different application contexts and ranking algorithms in mind, it is not straightforward which metric to choose for a given scenario. In this paper, we perform a comprehensive comparative analysis of existing group fairness metrics developed in the context of fair ranking. By virtue of their diverse application contexts, we argue that such a comparative analysis is not straightforward. Hence, we take an axiomatic approach whereby we design a set of thirteen properties for group fairness metrics that consider different ranking settings. A metric can then be selected depending on whether it satisfies all or a subset of these properties. We apply these properties on eleven existing group fairness metrics, and through both empirical and theoretical results we demonstrate that most of these metrics only satisfy a small subset of the proposed properties. These findings highlight limitations of existing metrics, and provide insights into how to evaluate and interpret different fairness metrics in practical deployment. The proposed properties can also assist practitioners in selecting appropriate metrics for evaluating fairness in a specific application.

Deep learning models operating in the complex domain are used due to their rich representation capacity. However, most of these models are either restricted to the first quadrant of the complex plane or project the complex-valued data into the real domain, causing a loss of information. This paper proposes that operating entirely in the complex domain increases the overall performance of complex-valued models. A novel, fully complex-valued learning scheme is proposed to train a Fully Complex-valued Convolutional Neural Network (FC-CNN) using a newly proposed complex-valued loss function and training strategy. Benchmarked on CIFAR-10, SVHN, and CIFAR-100, FC-CNN has a 4-10% gain compared to its real-valued counterpart, maintaining the model complexity. With fewer parameters, it achieves comparable performance to state-of-the-art complex-valued models on CIFAR-10 and SVHN. For the CIFAR-100 dataset, it achieves state-of-the-art performance with 25% fewer parameters. FC-CNN shows better training efficiency and much faster convergence than all the other models.

Building segmentation in high-resolution InSAR images is a challenging task that can be useful for large-scale surveillance. Although complex-valued deep learning networks perform better than their real-valued counterparts for complex-valued SAR data, phase information is not retained throughout the network, which causes a loss of information. This paper proposes a Fully Complex-valued, Fully Convolutional Multi-feature Fusion Network(FC2MFN) for building semantic segmentation on InSAR images using a novel, fully complex-valued learning scheme. The network learns multi-scale features, performs multi-feature fusion, and has a complex-valued output. For the particularity of complex-valued InSAR data, a new complex-valued pooling layer is proposed that compares complex numbers considering their magnitude and phase. This helps the network retain the phase information even through the pooling layer. Experimental results on the simulated InSAR dataset show that FC2MFN achieves better results compared to other state-of-the-art methods in terms of segmentation performance and model complexity.

Object detection and classification using aerial images is a challenging task as the information regarding targets are not abundant. Synthetic Aperture Radar(SAR) images can be used for Automatic Target Recognition(ATR) systems as it can operate in all-weather conditions and in low light settings. But, SAR images contain salt and pepper noise(speckle noise) that cause hindrance for the deep learning models to extract meaningful features. Using just aerial view Electro-optical(EO) images for ATR systems may also not result in high accuracy as these images are of low resolution and also do not provide ample information in extreme weather conditions. Therefore, information from multiple sensors can be used to enhance the performance of Automatic Target Recognition(ATR) systems. In this paper, we explore a methodology to use both EO and SAR sensor information to effectively improve the performance of the ATR systems by handling the shortcomings of each of the sensors. A novel Multi-Modal Domain Fusion(MDF) network is proposed to learn the domain invariant features from multi-modal data and use it to accurately classify the aerial view objects. The proposed MDF network achieves top-10 performance in the Track-1 with an accuracy of 25.3 % and top-5 performance in Track-2 with an accuracy of 34.26 % in the test phase on the PBVS MAVOC Challenge dataset [18].

Finetuning language models on a collection of datasets phrased as instructions has been shown to improve model performance and generalization to unseen tasks. In this paper we explore instruction finetuning with a particular focus on (1) scaling the number of tasks, (2) scaling the model size, and (3) finetuning on chain-of-thought data. We find that instruction finetuning with the above aspects dramatically improves performance on a variety of model classes (PaLM, T5, U-PaLM), prompting setups (zero-shot, few-shot, CoT), and evaluation benchmarks (MMLU, BBH, TyDiQA, MGSM, open-ended generation). For instance, Flan-PaLM 540B instruction-finetuned on 1.8K tasks outperforms PALM 540B by a large margin (+9.4% on average). Flan-PaLM 540B achieves state-of-the-art performance on several benchmarks, such as 75.2% on five-shot MMLU. We also publicly release Flan-T5 checkpoints, which achieve strong few-shot performance even compared to much larger models, such as PaLM 62B. Overall, instruction finetuning is a general method for improving the performance and usability of pretrained language models.

将模型参数适应传入数据流是深度学习可伸缩性的关键因素。有趣的是，在线设置中的先前持续学习策略无意中将其更新的参数锚定在本地参数子空间中，以记住旧任务，否则会偏离子空间并忘记。从这个观察结果，我们在构建多个参数模式和每个模式分配任务之间建立了权衡。模式优化的任务分配（MOTA），我们的贡献适应策略，并行训练多个模式，然后优化每个模式的任务分配。我们从经验上证明了基线连续学习策略以及各种分配变化的改进，即子人群，领域和任务转变。

培训低级的深层神经网络，即使用分解层，特别是社区感兴趣的：它在记忆消耗和训练时间方面提供了对未分离培训的效率。先前的工作集中在预训练的网络的低级近似值和低级空间中的培训中，并提供了其他目标，为所选实践提供了各种临时解释。我们分析了在实践中运作良好的技术，并通过对诸如GPT2之类的模型进行广泛的消融，我们提供了证据表明该领域的共同信念，这暗示着令人兴奋的研究机会仍然需要回答。

我们为旨在降低公平性的对抗神经网络（GNN）的对抗性攻击（GNN）的存在和有效性提供了证据。这些攻击可能不利基于GNN的节点分类中的特定节点子组，其中基础网络的节点具有敏感的属性，例如种族或性别。我们进行了定性和实验分析，以解释对抗链接注射如何损害GNN预测的公平性。例如，攻击者可以通过在属于相反子组和相反类标签的节点之间注入对抗性链接来损害基于GNN的节点分类的公平性。我们在经验数据集上的实验表明，对抗公平性攻击可以显着降低GNN预测的公平性（攻击是有效的），其扰动率较低（攻击是有效的），并且没有明显的准确性下降（攻击是欺骗性的）。这项工作证明了GNN模型对对抗公平性攻击的脆弱性。我们希望我们的发现在社区中提高人们对这个问题的认识，并为GNN模型的未来发展奠定了基础，这些模型对这种攻击更为强大。

深度学习的成功归功于我们能够相对轻松地解决某些大规模的非凸优化问题。尽管非凸优化是NP硬化，但简单的算法（通常是随机梯度下降的变体）在拟合大型神经网络的实践中具有令人惊讶的有效性。我们认为，在考虑了所有可能的隐藏单元对称对称性之后，神经网络损失景观包含（几乎）一个盆地。我们介绍了三种算法以缩小一个模型的单元，以使它们与参考模型的单位保持一致。这种转换产生了一组功能等效的权重，该权重位于参考模型附近的大约凸盆地中。在实验上，我们证明了各种模型架构和数据集中的单个盆地现象，包括在CIFAR-10和CIFAR-100上独立训练的Resnet模型之间的第一个（据我们所知）的（据我们所知）的第一次演示。此外，我们确定了有趣的现象，将模型宽度和训练时间与各种模型和数据集的模式连接性有关。最后，我们讨论了单个盆地理论的缺点，包括对线性模式连接假设的反例。