Africa
Learning knot invariants across dimensions
Craven, Jessica, Hughes, Mark, Jejjala, Vishnu, Kar, Arjun
We use deep neural networks to machine learn correlations between knot invariants in various dimensions. The three-dimensional invariant of interest is the Jones polynomial $J(q)$, and the four-dimensional invariants are the Khovanov polynomial $\text{Kh}(q,t)$, smooth slice genus $g$, and Rasmussen's $s$-invariant. We find that a two-layer feed-forward neural network can predict $s$ from $\text{Kh}(q,-q^{-4})$ with greater than $99\%$ accuracy. A theoretical explanation for this performance exists in knot theory via the now disproven knight move conjecture, which is obeyed by all knots in our dataset. More surprisingly, we find similar performance for the prediction of $s$ from $\text{Kh}(q,-q^{-2})$, which suggests a novel relationship between the Khovanov and Lee homology theories of a knot. The network predicts $g$ from $\text{Kh}(q,t)$ with similarly high accuracy, and we discuss the extent to which the machine is learning $s$ as opposed to $g$, since there is a general inequality $|s| \leq 2g$. The Jones polynomial, as a three-dimensional invariant, is not obviously related to $s$ or $g$, but the network achieves greater than $95\%$ accuracy in predicting either from $J(q)$. Moreover, similar accuracy can be achieved by evaluating $J(q)$ at roots of unity. This suggests a relationship with $SU(2)$ Chern--Simons theory, and we review the gauge theory construction of Khovanov homology which may be relevant for explaining the network's performance.
SpaBERT: A Pretrained Language Model from Geographic Data for Geo-Entity Representation
Li, Zekun, Kim, Jina, Chiang, Yao-Yi, Chen, Muhao
Named geographic entities (geo-entities for short) are the building blocks of many geographic datasets. Characterizing geo-entities is integral to various application domains, such as geo-intelligence and map comprehension, while a key challenge is to capture the spatial-varying context of an entity. We hypothesize that we shall know the characteristics of a geo-entity by its surrounding entities, similar to knowing word meanings by their linguistic context. Accordingly, we propose a novel spatial language model, SpaBERT, which provides a general-purpose geo-entity representation based on neighboring entities in geospatial data. SpaBERT extends BERT to capture linearized spatial context, while incorporating a spatial coordinate embedding mechanism to preserve spatial relations of entities in the 2-dimensional space. SpaBERT is pretrained with masked language modeling and masked entity prediction tasks to learn spatial dependencies. We apply SpaBERT to two downstream tasks: geo-entity typing and geo-entity linking. Compared with the existing language models that do not use spatial context, SpaBERT shows significant performance improvement on both tasks. We also analyze the entity representation from SpaBERT in various settings and the effect of spatial coordinate embedding.
Turning Fixed to Adaptive: Integrating Post-Evaluation into Simultaneous Machine Translation
Guo, Shoutao, Zhang, Shaolei, Feng, Yang
However, the previous methods, including fixed Simultaneous machine translation (SiMT) (Gu and adaptive policies, lack evaluation before taking et al., 2017; Ma et al., 2019; Arivazhagan et al., the next action. For fixed policy (Ma et al., 2019; 2019; Ma et al., 2020; Zhang and Feng, 2021b, Elbayad et al., 2020; Zhang et al., 2021; Zhang 2022d) starts translation before reading the whole and Feng, 2021c), the model generates translation source sentence. It seeks to achieve good latencyquality according to the predefined translation rules. Although tradeoffs and is suitable for various scenarios it only relies on simple training methods, with different latency tolerances. Compared to it cannot make full use of the context to decide an full-sentence machine translation, SiMT is more appropriate translation policy. For adaptive policy challenging because it lacks partial source content (Gu et al., 2017; Arivazhagan et al., 2019; Ma in translation and needs to decide on translation et al., 2020; Zhang et al., 2022), the model can policy additionally.
Feature selection intelligent algorithm with mutual information and steepest ascent strategy
Sarhrouni, Elkebir, Hammouch, Ahmed, Aboutajdine, Driss
Remote sensing is a higher technology to produce knowledge for data mining applications. In principle hyperspectral images (HSIs) is a remote sensing tool that provides precise classification of regions. The HSI contains more than a hundred of images of the ground truth (GT) map. Some images are carrying relevant information, but others describe redundant information, or they are affected by atmospheric noise. The aim is to reduce dimensionality of HSI. Many studies use mutual information (MI) or normalised forms of MI to select appropriate bands. In this paper we design an algorithm based also on MI, and we combine MI with steepest ascent algorithm, to improve a symmetric uncertainty coefficient-based strategy to select relevant bands for classification of HSI. This algorithm is a feature selection tool and a wrapper strategy. We perform our study on HSI AVIRIS 92AV3C. This is an artificial intelligent system to control redundancy; we had to clear the difference of the result's algorithm and the human decision, and this can be viewed as case study which human decision is perhaps different to an intelligent algorithm. Index Terms - Hyperspectral images, Classification, Fea-ture selection, Mutual Information, Redundancy, Steepest Ascent. Artificial Intelligence
P$^3$LM: Probabilistically Permuted Prophet Language Modeling for Generative Pre-Training
Bao, Junwei, Wang, Yifan, Ying, Jiangyong, Gong, Yeyun, Zhao, Jing, Wu, Youzheng, He, Xiaodong
Conventional autoregressive left-to-right (L2R) sequence generation faces two issues during decoding: limited to unidirectional target sequence modeling, and constrained on strong local dependencies. To address the aforementioned problem, we propose P$^3$LM, a probabilistically permuted prophet language model, which strengthens the modeling of bidirectional information and long token dependencies for sequence generation. Specifically, P$^3$LM learns to generate tokens in permuted order upon an order-aware transformer decoder, as well as to generate the corresponding future $N$ tokens with a multi-stream attention mechanism. Extensive experiments are conducted on the GLGE benchmark, which includes four datasets for summarization, two for question generation, one for conversational question answering, and one for dialog response generation, where P$^3$LM achieves state-of-the-art results compared with strong publicly available generative pre-training methods.
A Benchmark Study of Contrastive Learning for Arabic Social Meaning
Khondaker, Md Tawkat Islam, Nagoudi, El Moatez Billah, Elmadany, AbdelRahim, Abdul-Mageed, Muhammad, Lakshmanan, Laks V. S.
Contrastive learning (CL) brought significant progress to various NLP tasks. Despite this progress, CL has not been applied to Arabic NLP to date. Nor is it clear how much benefits it could bring to particular classes of tasks such as those involved in Arabic social meaning (e.g., sentiment analysis, dialect identification, hate speech detection). In this work, we present a comprehensive benchmark study of state-of-the-art supervised CL methods on a wide array of Arabic social meaning tasks. Through extensive empirical analyses, we show that CL methods outperform vanilla finetuning on most tasks we consider. We also show that CL can be data efficient and quantify this efficiency. Overall, our work allows us to demonstrate the promise of CL methods, including in low-resource settings.
Enhancing Tabular Reasoning with Pattern Exploiting Training
Shankarampeta, Abhilash Reddy, Gupta, Vivek, Zhang, Shuo
Recent methods based on pre-trained language models have exhibited superior performance over tabular tasks (e.g., tabular NLI), despite showing inherent problems such as not using the right evidence and inconsistent predictions across inputs while reasoning over the tabular data. In this work, we utilize Pattern-Exploiting Training (PET) (i.e., strategic MLM) on pre-trained language models to strengthen these tabular reasoning models' pre-existing knowledge and reasoning abilities. Our upgraded model exhibits a superior understanding of knowledge facts and tabular reasoning compared to current baselines. Additionally, we demonstrate that such models are more effective for underlying downstream tasks of tabular inference on InfoTabs. Furthermore, we show our model's robustness against adversarial sets generated through various character and word level perturbations.
Benchmarking GPU and TPU Performance with Graph Neural Networks
Ju, xiangyang, Wang, Yunsong, Murnane, Daniel, Choma, Nicholas, Farrell, Steven, Calafiura, Paolo
Many artificial intelligence (AI) devices have been developed to accelerate the training and inference of neural networks models. The most common ones are the Graphics Processing Unit (GPU) and Tensor Processing Unit (TPU). They are highly optimized for dense data representations. However, sparse representations such as graphs are prevalent in many domains, including science. It is therefore important to characterize the performance of available AI accelerators on sparse data. This work analyzes and compares the GPU and TPU performance training a Graph Neural Network (GNN) developed to solve a real-life pattern recognition problem. Characterizing the new class of models acting on sparse data may prove helpful in optimizing the design of deep learning libraries and future AI accelerators.
DL-Corrector-Remapper: A grid-free bias-correction deep learning methodology for data-driven high-resolution global weather forecasting
Ge, Tao, Pathak, Jaideep, Subramaniam, Akshay, Kashinath, Karthik
Data-driven models, such as FourCastNet (FCN), have shown exemplary performance in high-resolution global weather forecasting. This performance, however, is based on supervision on mesh-gridded weather data without the utilization of raw climate observational data, the gold standard ground truth. In this work we develop a methodology to correct, remap, and fine-tune gridded uniform forecasts of FCN so it can be directly compared against observational ground truth, which is sparse and non-uniform in space and time. This is akin to bias correction and post-processing of numerical weather prediction (NWP), a routine operation at meteorological and weather forecasting centers across the globe. The Adaptive Fourier Neural Operator (AFNO) architecture is used as the backbone to learn continuous representations of the atmosphere. The spatially and temporally non-uniform output is evaluated by the non-uniform discrete inverse Fourier transform (NUIDFT) given the output query locations. We call this network the Deep-Learning-Corrector-Remapper (DLCR). The improvement in DLCR's performance against the gold standard ground truth over the baseline's performance shows its potential to correct, remap, and fine-tune the mesh-gridded forecasts under the supervision of observations.
A baseline revisited: Pushing the limits of multi-segment models for context-aware translation
Majumder, Suvodeep, Lauly, Stanislas, Nadejde, Maria, Federico, Marcello, Dinu, Georgiana
We show that multi-sentence translation can The quality of NMT (Neural Machine Translation) benefit from increased-capacity transformer models has been improving over the years and models and that deeper models are better at is narrowing the gap to human translation performance learning contextual dependencies than wider (Hassan et al., 2018). Until recently, most models. of the MT research has focused on translating and evaluating sentences in isolation, ignoring the context We further show that distilled models can in which these sentences occur. Simplifying learn contextual dependencies from larger the translation task this way has its advantages: models, while reducing computational cost data sets are easier to create, models are computationally and increasing robustness to input length variations.