Africa
Improving Distantly-Supervised Named Entity Recognition with Self-Collaborative Denoising Learning
Zhang, Xinghua, Yu, Bowen, Liu, Tingwen, Zhang, Zhenyu, Sheng, Jiawei, Xue, Mengge, Xu, Hongbo
Distantly supervised named entity recognition (DS-NER) efficiently reduces labor costs but meanwhile intrinsically suffers from the label noise due to the strong assumption of distant supervision. Typically, the wrongly labeled instances comprise numbers of incomplete and inaccurate annotation noise, while most prior denoising works are only concerned with one kind of noise and fail to fully explore useful information in the whole training set. To address this issue, we propose a robust learning paradigm named Self-Collaborative Denoising Learning (SCDL), which jointly trains two teacher-student networks in a mutually-beneficial manner to iteratively perform noisy label refinery. Each network is designed to exploit reliable labels via self denoising, and two networks communicate with each other to explore unreliable annotations by collaborative denoising. Extensive experimental results on five real-world datasets demonstrate that SCDL is superior to state-of-the-art DS-NER denoising methods.
Estimating Causal Effects Under Image Confounding Bias with an Application to Poverty in Africa
Jerzak, Connor T., Johansson, Fredrik, Daoud, Adel
Observational studies of causal effects require adjustment for confounding factors. In the tabular setting, where these factors are well-defined, separate random variables, the effect of confounding is well understood. However, in public policy, ecology, and in medicine, decisions are often made in non-tabular settings, informed by patterns or objects detected in images (e.g., maps, satellite or tomography imagery). Using such imagery for causal inference presents an opportunity because objects in the image may be related to the treatment and outcome of interest. In these cases, we rely on the images to adjust for confounding but observed data do not directly label the existence of the important objects. Motivated by real-world applications, we formalize this challenge, how it can be handled, and what conditions are sufficient to identify and estimate causal effects. We analyze finite-sample performance using simulation experiments, estimating effects using a propensity adjustment algorithm that employs a machine learning model to estimate the image confounding. Our experiments also examine sensitivity to misspecification of the image pattern mechanism. Finally, we use our methodology to estimate the effects of policy interventions on poverty in African communities from satellite imagery.
Robust Mid-Pass Filtering Graph Convolutional Networks
Huang, Jincheng, Du, Lun, Chen, Xu, Fu, Qiang, Han, Shi, Zhang, Dongmei
Graph convolutional networks (GCNs) are currently the most promising paradigm for dealing with graph-structure data, while recent studies have also shown that GCNs are vulnerable to adversarial attacks. Thus developing GCN models that are robust to such attacks become a hot research topic. However, the structural purification learning-based or robustness constraints-based defense GCN methods are usually designed for specific data or attacks, and introduce additional objective that is not for classification. Extra training overhead is also required in their design. To address these challenges, we conduct in-depth explorations on mid-frequency signals on graphs and propose a simple yet effective Mid-pass filter GCN (Mid-GCN). Theoretical analyses guarantee the robustness of signals through the mid-pass filter, and we also shed light on the properties of different frequency signals under adversarial attacks. Extensive experiments on six benchmark graph data further verify the effectiveness of our designed Mid-GCN in node classification accuracy compared to state-of-the-art GCNs under various adversarial attack strategies.
Meeting the Needs of Low-Resource Languages: The Value of Automatic Alignments via Pretrained Models
Ebrahimi, Abteen, McCarthy, Arya D., Oncevay, Arturo, Chiruzzo, Luis, Ortega, John E., Gimรฉnez-Lugo, Gustavo A., Coto-Solano, Rolando, Kann, Katharina
Large multilingual models have inspired a new class of word alignment methods, which work well for the model's pretraining languages. However, the languages most in need of automatic alignment are low-resource and, thus, not typically included in the pretraining data. In this work, we ask: How do modern aligners perform on unseen languages, and are they better than traditional methods? We contribute gold-standard alignments for Bribri--Spanish, Guarani--Spanish, Quechua--Spanish, and Shipibo-Konibo--Spanish. With these, we evaluate state-of-the-art aligners with and without model adaptation to the target language. Finally, we also evaluate the resulting alignments extrinsically through two downstream tasks: named entity recognition and part-of-speech tagging. We find that although transformer-based methods generally outperform traditional models, the two classes of approach remain competitive with each other.
Exploring the Limits of ChatGPT for Query or Aspect-based Text Summarization
Yang, Xianjun, Li, Yan, Zhang, Xinlu, Chen, Haifeng, Cheng, Wei
Text summarization has been a crucial problem in natural language processing (NLP) for several decades. It aims to condense lengthy documents into shorter versions while retaining the most critical information. Various methods have been proposed for text summarization, including extractive and abstractive summarization. The emergence of large language models (LLMs) like GPT3 and ChatGPT has recently created significant interest in using these models for text summarization tasks. Recent studies \cite{goyal2022news, zhang2023benchmarking} have shown that LLMs-generated news summaries are already on par with humans. However, the performance of LLMs for more practical applications like aspect or query-based summaries is underexplored. To fill this gap, we conducted an evaluation of ChatGPT's performance on four widely used benchmark datasets, encompassing diverse summaries from Reddit posts, news articles, dialogue meetings, and stories. Our experiments reveal that ChatGPT's performance is comparable to traditional fine-tuning methods in terms of Rouge scores. Moreover, we highlight some unique differences between ChatGPT-generated summaries and human references, providing valuable insights into the superpower of ChatGPT for diverse text summarization tasks. Our findings call for new directions in this area, and we plan to conduct further research to systematically examine the characteristics of ChatGPT-generated summaries through extensive human evaluation.
Over-parametrization via Lifting for Low-rank Matrix Sensing: Conversion of Spurious Solutions to Strict Saddle Points
Ma, Ziye, Molybog, Igor, Lavaei, Javad, Sojoudi, Somayeh
This paper studies the role of over-parametrization in solving non-convex optimization problems. The focus is on the important class of low-rank matrix sensing, where we propose an infinite hierarchy of non-convex problems via the lifting technique and the Burer-Monteiro factorization. This contrasts with the existing over-parametrization technique where the search rank is limited by the dimension of the matrix and it does not allow a rich over-parametrization of an arbitrary degree. We show that although the spurious solutions of the problem remain stationary points through the hierarchy, they will be transformed into strict saddle points (under some technical conditions) and can be escaped via local search methods. This is the first result in the literature showing that over-parametrization creates a negative curvature for escaping spurious solutions. We also derive a bound on how much over-parametrization is requited to enable the elimination of spurious solutions.
A Convolutional-based Model for Early Prediction of Alzheimer's based on the Dementia Stage in the MRI Brain Images
Pellakur, Shrish, Elsayed, Nelly, ElSayed, Zag, Ozer, Murat
Alzheimer's disease is a degenerative brain disease. Being the primary cause of Dementia in adults and progressively destroys brain memory. Though Alzheimer's disease does not have a cure currently, diagnosing it at an earlier stage will help reduce the severity of the disease. Thus, early diagnosis of Alzheimer's could help to reduce or stop the disease from progressing. In this paper, we proposed a deep convolutional neural network-based model for learning model using to determine the stage of Dementia in adults based on the Magnetic Resonance Imaging (MRI) images to detect the early onset of Alzheimer's.
US condemns Russian use of Iranian drones in Ukraine
American defense officials on Tuesday sought to dispel any doubt that Iran is supplying drones for Russia's war in Ukraine, releasing photos and analysis of unmanned aircraft deployed in the conflict to demonstrate Tehran's involvement. During a briefing in London, analysts from the Defense Intelligence Agency displayed photos of drones that attacked Ukraine alongside images of those previously traced to Iran. A comparison of design details such as tail fins, nose cones and landing gear shows that the weapons used in Ukraine are "indistinguishable" from Shahed-131 and -136 attack drones and Mohajer 6 unmanned aerial vehicles used in the Middle East. The effort to "show the homework'' is intended to help persuade governments or international agencies of Tehran's involvement. Iran has said it supplied a "small number" of drones to Russia before the invasion of Ukraine but has denied providing any more since troops crossed the border last February. The evidence proves otherwise, an official from the Defense Intelligence Agency said while speaking on condition of anonymity because of the sensitivity of the information. "Iran is a partner in the conflict with Russia,'' the official said.
Chinese leader Xi Jinping expresses support for Iran during meeting with Ebrahim Raisi
Fox News Flash top headlines are here. Check out what's clicking on Foxnews.com. Chinese leader Xi Jinping expressed support for Iran during a visit by its president on Tuesday as Tehran tries to expand relations with Beijing and Moscow to offset Western sanctions over its nuclear development. The official Chinese account of Xi's meeting with Ebrahim Raisi gave no indication whether they discussed Russia's attack on Ukraine. Tehran supplied military drones to Russian President Vladimir Putin's government but says they were delivered before the war began.
ChatGPT frenzy sweeps China as firms scramble for home-grown options - abtlive
Microsoft-backed OpenAI has kept its hit ChatGPT app off-limits to users in China, but the app is attracting huge interest in the country, with firms rushing to integrate the technology into their products and launch rival solutions. While residents in the country are unable to create OpenAI accounts to access the artificial intelligence-powered (AI) chatbot, virtual private networks and foreign phone numbers are helping some bypass those restrictions. At the same time, the OpenAI models behind the ChatGPT programme, which can write essays, recipes and complex computer code, are relatively accessible in China and increasingly being incorporated into Chinese consumer technology applications from social networks to online shopping. The tool's surging popularity is rapidly raising awareness in China about how advanced U.S. AI is and, according to analysts, just how far behind tech firms in the world's second-largest economy are as they scramble to catch up. "There is huge excitement around ChatGPT. Unlike the metaverse which faces huge difficulty in finding real-life application, ChatGPT has suddenly helped us achieve human-computer interaction," said Ding Daoshi, director of Beijing-based internet consultancy Sootoo.