Buffalo
Mixture of neural operator experts for learning boundary conditions and model selection
Deighan, Dwyer, Actor, Jonas A., Patel, Ravi G.
While Fourier-based neural operators are best suited to learning mappings between functions on periodic domains, several works have introduced techniques for incorporating non trivial boundary conditions. However, all previously introduced methods have restrictions that limit their applicability. In this work, we introduce an alternative approach to imposing boundary conditions inspired by volume penalization from numerical methods and Mixture of Experts (MoE) from machine learning. By introducing competing experts, the approach additionally allows for model selection. To demonstrate the method, we combine a spatially conditioned MoE with the Fourier based, Modal Operator Regression for Physics (MOR-Physics) neural operator and recover a nonlinear operator on a disk and quarter disk. Next, we extract a large eddy simulation (LES) model from direct numerical simulation of channel flow and show the domain decomposition provided by our approach. Finally, we train our LES model with Bayesian variational inference and obtain posterior predictive samples of flow far past the DNS simulation time horizon.
Advance Detection Of Bull And Bear Phases In Cryptocurrency Markets
Arulkumaran, Rahul, Kumar, Suyash, Tomar, Shikha, Gongalla, Manideep, Harshitha, null
Cryptocurrencies are highly volatile financial instruments with more and more new retail investors joining the scene with each passing day. Bitcoin has always proved to determine in which way the rest of the cryptocurrency market is headed towards. As of today Bitcoin has a market dominance of close to 50 percent. Bull and bear phases in cryptocurrencies are determined based on the performance of Bitcoin over the 50 Day and 200 Day Moving Averages. The aim of this paper is to foretell the performance of bitcoin in the near future by employing predictive algorithms. This predicted data will then be used to calculate the 50 Day and 200 Day Moving Averages and subsequently plotted to establish the potential bull and bear phases.
Conditional Image Synthesis with Diffusion Models: A Survey
Zhan, Zheyuan, Chen, Defang, Mei, Jian-Ping, Zhao, Zhenghe, Chen, Jiawei, Chen, Chun, Lyu, Siwei, Wang, Can
Conditional image synthesis based on user-specified requirements is a key component in creating complex visual content. In recent years, diffusion-based generative modeling has become a highly effective way for conditional image synthesis, leading to exponential growth in the literature. However, the complexity of diffusion-based modeling, the wide range of image synthesis tasks, and the diversity of conditioning mechanisms present significant challenges for researchers to keep up with rapid developments and understand the core concepts on this topic. In this survey, we categorize existing works based on how conditions are integrated into the two fundamental components of diffusion-based modeling, i.e., the denoising network and the sampling process. We specifically highlight the underlying principles, advantages, and potential challenges of various conditioning approaches in the training, re-purposing, and specialization stages to construct a desired denoising network. We also summarize six mainstream conditioning mechanisms in the essential sampling process. All discussions are centered around popular applications. Finally, we pinpoint some critical yet still open problems to be solved in the future and suggest some possible solutions. Our reviewed works are itemized at https://github.com/zju-pi/Awesome-Conditional-Diffusion-Models.
PyGRF: An improved Python Geographical Random Forest model and case studies in public health and natural disasters
Sun, Kai, Zhou, Ryan Zhenqi, Kim, Jiyeon, Hu, Yingjie
Geographical random forest (GRF) is a recently developed and spatially explicit machine learning model. With the ability to provide more accurate predictions and local interpretations, GRF has already been used in many studies. The current GRF model, however, has limitations in its determination of the local model weight and bandwidth hyperparameters, potentially insufficient numbers of local training samples, and sometimes high local prediction errors. Also, implemented as an R package, GRF currently does not have a Python version which limits its adoption among machine learning practitioners who prefer Python. This work addresses these limitations by introducing theory-informed hyperparameter determination, local training sample expansion, and spatially-weighted local prediction. We also develop a Python-based GRF model and package, PyGRF, to facilitate the use of the model. We evaluate the performance of PyGRF on an example dataset and further demonstrate its use in two case studies in public health and natural disasters.
Self-Supervised Learning Based Handwriting Verification
Chauhan, Mihir, Shaikh, Mohammad Abuzar, Ramamurthy, Bina, Gao, Mingchen, Lyu, Siwei, Srihari, Sargur
We present SSL-HV: Self-Supervised Learning approaches applied to the task of Handwriting Verification. This task involves determining whether a given pair of handwritten images originate from the same or different writer distribution. We have compared the performance of multiple generative, contrastive SSL approaches against handcrafted feature extractors and supervised learning on CEDAR AND dataset. We show that ResNet based Variational Auto-Encoder (VAE) outperforms other generative approaches achieving 76.3% accuracy, while ResNet-18 fine-tuned using Variance-Invariance-Covariance Regularization (VICReg) outperforms other contrastive approaches achieving 78% accuracy. Using a pre-trained VAE and VICReg for the downstream task of writer verification we observed a relative improvement in accuracy of 6.7% and 9% over ResNet-18 supervised baseline with 10% writer labels.
The Morning After: Apple allows game emulators on the App Store
Apple, in its latest update to its App Store developer guidelines for iPhones and iPads, flagged by 9to5Mac, says it will allow game console emulators โ and even downloadable games. Apple warns developers, however, they "are responsible for all such software offered in [their] app, including ensuring that such software complies with these Guidelines and all applicable laws." So don't expect to play Super Mario, Spyro, or a third game series that starts with an'S'. Meanwhile, we have a guide to watching (and recording) the total eclipse in North America later today. The best chance of good viewing along the path of eclipse totality is still in northeastern parts of the US (Buffalo, NY, Burlington, VT) and southeast Canada (Niagara Falls and Montreal).
Tesla Autopilot workers are seeking to unionize in New York
A group of Tesla workers in New York has sent company chief Elon Musk a letter stating their intention to unionize, according to Bloomberg. It could end up being the first Tesla union if successful, seeing as previous attempts fizzled out before organizers could petition for a vote. The employees involved in the campaign are in charge of labeling data for Tesla's Autopilot technology at the company's Buffalo, New York facility. Bloomberg says the group is asking for better pay, job security and a better work environment that eases the production pressures placed on them. Workers told the news organization that they've been skipping bathroom breaks, since Tesla keeps a close eye on their every move.
The ethics of artificial intelligence
Maura R. Grossman, JD, Ph.D., is a Research Professor in the Cheriton School of Computer Science, an Adjunct Professor at Osgoode Hall Law School, and an affiliate faculty member of the Vector Institute for Artificial Intelligence. She is also Principal at Maura Grossman Law, an eDiscovery law and consulting firm in Buffalo, New York. Maura is best known for her work on technology-assisted review, a supervised machine learning approach that she and her colleague, Computer Science Professor Gordon V. Cormack, developed to expedite review of documents in high-stakes litigation. She teaches Artificial Intelligence: Law, Ethics, and Policy, a course for graduate computer science students at Waterloo and upper-class law students at Osgoode, as well as the ethics workshop required of all students in the master's programs in artificial intelligence and data science at Waterloo. Artificial intelligence is an umbrella term first used at a conference in Dartmouth in 1956.
LAViTeR: Learning Aligned Visual and Textual Representations Assisted by Image and Caption Generation
Shaikh, Mohammad Abuzar, Ji, Zhanghexuan, Moukheiber, Dana, Srihari, Sargur, Gao, Mingchen
Pre-training visual and textual representations from large-scale image-text pairs is becoming a standard approach for many downstream vision-language tasks. The transformer-based models learn inter and intra-modal attention through a list of self-supervised learning tasks. This paper proposes LAViTeR, a novel architecture for visual and textual representation learning. The main module, Visual Textual Alignment (VTA) will be assisted by two auxiliary tasks, GAN-based image synthesis and Image Captioning. We also propose a new evaluation metric measuring the similarity between the learnt visual and textual embedding. The experimental results on two public datasets, CUB and MS-COCO, demonstrate superior visual and textual representation alignment in the joint feature embedding space
Improving Joint Learning of Chest X-Ray and Radiology Report by Word Region Alignment
Ji, Zhanghexuan, Shaikh, Mohammad Abuzar, Moukheiber, Dana, Srihari, Sargur, Peng, Yifan, Gao, Mingchen
Self-supervised learning provides an opportunity to explore unlabeled chest X-rays and their associated free-text reports accumulated in clinical routine without manual supervision. This paper proposes a Joint Image Text Representation Learning Network (JoImTeRNet) for pre-training on chest X-ray images and their radiology reports. The model was pre-trained on both the global image-sentence level and the local image region-word level for visual-textual matching. Both are bidirectionally constrained on Cross-Entropy based and ranking-based Triplet Matching Losses. The region-word matching is calculated using the attention mechanism without direct supervision about their mapping. The pre-trained multi-modal representation learning paves the way for downstream tasks concerning image and/or text encoding. We demonstrate the representation learning quality by cross-modality retrievals and multilabel classifications on two datasets: OpenI-IU and MIMIC-CXR.