Africa
Wavelet Packet Power Spectrum Kullback-Leibler Divergence: A New Metric for Image Synthesis
Veeramacheneni, Lokesh, Wolter, Moritz, Gall, Juergen
Current metrics for generative neural networks are biased towards low frequencies, specific generators, objects from the ImageNet dataset, and value texture more than shape. Many current quality metrics do not measure frequency information directly. In response, we propose a new frequency band-based quality metric, which opens a door into the frequency domain yet, at the same time, preserves spatial aspects of the data. Our metric works well even if the distributions we compare are far from ImageNet or have been produced by differing generator architectures. We verify the quality of our metric by sampling a broad selection of generative networks on a wide variety of data sets. A user study ensures our metric aligns with human perception. Furthermore, we show that frequency band guidance can improve the frequency domain fidelity of a current generative network.
Efficient Deformable Tissue Reconstruction via Orthogonal Neural Plane
Yang, Chen, Wang, Kailing, Wang, Yuehao, Dou, Qi, Yang, Xiaokang, Shen, Wei
Intraoperative imaging techniques for reconstructing deformable tissues in vivo are pivotal for advanced surgical systems. Existing methods either compromise on rendering quality or are excessively computationally intensive, often demanding dozens of hours to perform, which significantly hinders their practical application. In this paper, we introduce Fast Orthogonal Plane (Forplane), a novel, efficient framework based on neural radiance fields (NeRF) for the reconstruction of deformable tissues. We conceptualize surgical procedures as 4D volumes, and break them down into static and dynamic fields comprised of orthogonal neural planes. This factorization iscretizes the four-dimensional space, leading to a decreased memory usage and faster optimization. A spatiotemporal importance sampling scheme is introduced to improve performance in regions with tool occlusion as well as large motions and accelerate training. An efficient ray marching method is applied to skip sampling among empty regions, significantly improving inference speed. Forplane accommodates both binocular and monocular endoscopy videos, demonstrating its extensive applicability and flexibility. Our experiments, carried out on two in vivo datasets, the EndoNeRF and Hamlyn datasets, demonstrate the effectiveness of our framework. In all cases, Forplane substantially accelerates both the optimization process (by over 100 times) and the inference process (by over 15 times) while maintaining or even improving the quality across a variety of non-rigid deformations. This significant performance improvement promises to be a valuable asset for future intraoperative surgical applications. The code of our project is now available at https://github.com/Loping151/ForPlane.
A Theory of Non-Acyclic Generative Flow Networks
Brunswic, Leo Maxime, Li, Yinchuan, Xu, Yushun, Jui, Shangling, Ma, Lizhuang
GFlowNets is a novel flow-based method for learning a stochastic policy to generate objects via a sequence of actions and with probability proportional to a given positive reward. We contribute to relaxing hypotheses limiting the application range of GFlowNets, in particular: acyclicity (or lack thereof). To this end, we extend the theory of GFlowNets on measurable spaces which includes continuous state spaces without cycle restrictions, and provide a generalization of cycles in this generalized context. We show that losses used so far push flows to get stuck into cycles and we define a family of losses solving this issue. Experiments on graphs and continuous tasks validate those principles.
Down the Toxicity Rabbit Hole: Investigating PaLM 2 Guardrails
Khorramrouz, Adel, Dutta, Sujan, Dutta, Arka, KhudaBukhsh, Ashiqur R.
This paper conducts a robustness audit of the safety feedback of PaLM 2 through a novel toxicity rabbit hole framework introduced here. Starting with a stereotype, the framework instructs PaLM 2 to generate more toxic content than the stereotype. Every subsequent iteration it continues instructing PaLM 2 to generate more toxic content than the previous iteration until PaLM 2 safety guardrails throw a safety violation. Our experiments uncover highly disturbing antisemitic, Islamophobic, racist, homophobic, and misogynistic (to list a few) generated content that PaLM 2 safety guardrails do not evaluate as highly unsafe. We briefly discuss the generalizability of this framework across eight other large language models.
Chain-of-Questions Training with Latent Answers for Robust Multistep Question Answering
Zhu, Wang, Thomason, Jesse, Jia, Robin
We train a language model (LM) to robustly answer multistep questions by generating and answering sub-questions. We propose Chain-of-Questions, a framework that trains a model to generate sub-questions and sub-answers one at a time by leveraging human annotated question decomposition meaning representation (QDMR). The key technical challenge is that QDMR only contains sub-questions but not answers to those sub-questions, so we treat sub-answers as latent variables and optimize them using a novel dynamic mixture of Hard-EM and MAPO. Chain-of-Questions greatly outperforms strong neuro-symbolic methods by 9.0 F1 on DROP contrast set, and outperforms GPT-3.5 by 24.3 F1 on HOTPOTQA adversarial set, thus demonstrating the effectiveness and robustness of our framework.
The 16 Best Books of 2023
It's hard to find something pithy to say about 2023, a year of dissonant extremes, when wildfires devoured Canadian forests, Twitter withered into X, the Titan submersible imploded into infamy, Silicon Valley's power players rejoiced over the rise of generative AI, scientists cheered Crispr treatment breakthroughs, peace activists became terrorist-attack victims, and the world despaired over the thousands of children killed in Gaza. It is, frequently, a painful one. Appropriate, then, that this was a year for unwieldy, searching, big-swing books. Doorstoppers and sagas rose to the moment, providing insight into an increasingly inscrutable world even when they couldn't provide comfort. As always, this is an idiosyncratic, incomplete, and subjective list, the result of one person's avid but disorganized reading schedule.
Data Bias Management
The presence of bias in data has led to a lot of research being conducted to understand the impact of bias on machine learning (ML) models and data-driven decision-making systems.2 Research has focused on questions related to the fairness in the decisions taken by models trained with biased data, and on designing methods to increase the transparency of automated decision-making processes so that possible bias issues may be easily spotted and "fixed" by removing bias. Recent approaches taken in the literature to deal with data bias first aim to understand the cause of the problem (for example, a subset of the population being underrepresented in the training dataset) and then propose and evaluate an ad hoc intervention to reduce or remove the bias from the system (for example, by selecting which additional training data items to label in order to rebalance the dataset and increase equality--that is, a balanced representation of classes--rather than equity--that is, overrepresenting the disadvantaged subset of the population. Example research on bias removal include work looking at how to remove bias from learned word embeddings. Bolukbasi et al.3 defined a methodology for modifying an embedding representation to remove gender stereotypes.
Large Scale Foundation Models for Intelligent Manufacturing Applications: A Survey
Zhang, Haotian, Dereck, Semujju Stuart, Wang, Zhicheng, Lv, Xianwei, Xu, Kang, Wu, Liang, Jia, Ye, Wu, Jing, Long, Zhuo, Liang, Wensheng, Ma, X. G., Zhuang, Ruiyan
Although the applications of artificial intelligence especially deep learning had greatly improved various aspects of intelligent manufacturing, they still face challenges for wide employment due to the poor generalization ability, difficulties to establish high-quality training datasets, and unsatisfactory performance of deep learning methods. The emergence of large scale foundational models(LSFMs) had triggered a wave in the field of artificial intelligence, shifting deep learning models from single-task, single-modal, limited data patterns to a paradigm encompassing diverse tasks, multimodal, and pre-training on massive datasets. Although LSFMs had demonstrated powerful generalization capabilities, automatic high-quality training dataset generation and superior performance across various domains, applications of LSFMs on intelligent manufacturing were still in their nascent stage. A systematic overview of this topic was lacking, especially regarding which challenges of deep learning can be addressed by LSFMs and how these challenges can be systematically tackled. To fill this gap, this paper systematically expounded current statue of LSFMs and their advantages in the context of intelligent manufacturing. and compared comprehensively with the challenges faced by current deep learning models in various intelligent manufacturing applications. We also outlined the roadmaps for utilizing LSFMs to address these challenges. Finally, case studies of applications of LSFMs in real-world intelligent manufacturing scenarios were presented to illustrate how LSFMs could help industries, improve their efficiency.
Predicting Confinement Effect of Carbon Fiber Reinforced Polymers on Strength of Concrete using Metaheuristics-based Artificial Neural Networks
Wahab, Sarmed, Suleiman, Mohamed, Shabbir, Faisal, Mahmoudabadi, Nasim Shakouri, Waqas, Sarmad, Herl, Nouman, Ahmad, Afaq
Keywords: carbon fiber reinforced polymer, concrete, confinement effect, strength, particle swarm optimization, grey wolf optimizer, bat algorithm Abstract This article deals with the study of predicting the confinement effect of carbon fiber reinforced polymers (CFRPs) on concrete cylinder strength using metaheuristics-based artificial neural networks. Three metaheuristic models are implemented including particle swarm optimization (PSO), grey wolf optimizer (GWO), and bat algorithm (BA). These algorithms are trained on the data using an objective function of mean square error and their predicted results are validated against the experimental studies and finite element analysis. The study shows that the hybrid model of PSO predicted the strength of CFRP-confined concrete cylinders with maximum accuracy of 99.13% and GWO predicted the results with an accuracy of 98.17%. The high accuracy of axial compressive strength predictions demonstrated that these prediction models are a reliable solution to the empirical methods. The prediction models are especially suitable for avoiding full-scale time-consuming experimental tests that make the process quick and economical. 1 Introduction Fiber-reinforced polymer is a composite material comprising fibers of either glass, aramid, or carbon and a polymer matrix. These fibers improve the properties of the polymer matrix mechanically including its stiffness and strength. The popularity of these composites has increased significantly in civil engineering due to their ability to strengthen concrete structural members. FRPs can be used either as a bar or plates embedded in concrete as an internal reinforcement and can be used as an external reinforcement by wrapping FRP sheets to existing structural members. The FRP bars have significantly higher strength than the steel reinforcement bars. They are highly durable and resistant to chemicals, corrosion (Cousin et al. 2019, Ananthkumar et al. 2020, Zhang et al. 2020), and radiation, their higher strength-to-weight ratio (Zhou et al. 2019) makes them ideal for structures that require high strength but need not be heavy. They can be molded into any required shape that provides higher design flexibility. Moreover, it has a lower environmental impact (Lee and Jain 2009), unlike concrete and timber.
Dynamic Routing for Integrated Satellite-Terrestrial Networks: A Constrained Multi-Agent Reinforcement Learning Approach
Lyu, Yifeng, Hu, Han, Fan, Rongfei, Liu, Zhi, An, Jianping, Mao, Shiwen
The integrated satellite-terrestrial network (ISTN) system has experienced significant growth, offering seamless communication services in remote areas with limited terrestrial infrastructure. However, designing a routing scheme for ISTN is exceedingly difficult, primarily due to the heightened complexity resulting from the inclusion of additional ground stations, along with the requirement to satisfy various constraints related to satellite service quality. To address these challenges, we study packet routing with ground stations and satellites working jointly to transmit packets, while prioritizing fast communication and meeting energy efficiency and packet loss requirements. Specifically, we formulate the problem of packet routing with constraints as a max-min problem using the Lagrange method. Then we propose a novel constrained Multi-Agent reinforcement learning (MARL) dynamic routing algorithm named CMADR, which efficiently balances objective improvement and constraint satisfaction during the updating of policy and Lagrange multipliers. Finally, we conduct extensive experiments and an ablation study using the OneWeb and Telesat mega-constellations. Results demonstrate that CMADR reduces the packet delay by a minimum of 21% and 15%, while meeting stringent energy consumption and packet loss rate constraints, outperforming several baseline algorithms.