Africa
Spectroscopy and Chemometrics/Machine-Learning News Weekly #6, 2023 – [:en]NIR Calibration Model[:de]NIR Calibration Model[:it]Modelli di Calibrazione NIR
Get the Spectroscopy and Chemometrics News Weekly in real time on Twitter @ CalibModel and follow us. "Component Prediction of Antai Pills Based on One-Dimensional Convolutional Neural Network and Near-Infrared Spectroscopy" LINK "Moisture content monitoring in withering leaves during black tea processing based on electronic eye and near infrared spectroscopy" LINK "Hyperspectral technique combined with stacking and blending ensemble learning method for detection of cadmium content in oilseed rape leaves" LINK "Capacitance spectroscopy enables realtime monitoring of early cell death in mammalian cell culture" LINK "Detection of bruised loquats based on reflectance, absorbance and Kubelka-Munk spectra" LINK "Longitudinal alterations of pulmonary [… formula…] O2 on-kinetics during moderate-intensity exercise in competitive youth cyclists are related to alterations in the …" LINK
Ukraine: Lessons For War In The Middle East And Taiwan
The tanks and trench warfare in Ukraine may seem old-school, but US experts say the conflict has provided strategic insights into future possible conflicts from the Middle East to Taiwan. They range from the mundane -- the need for bigger weapons stockpiles -- to the high-tech, with Ukraine a proving ground for artificial intelligence and robotic warfare. Ukraine has been a test for "sensor fusion," triangulating diverse sources of information to create a fuller picture of the battlefield, said Stephen Biddle, a defense expert at Columbia University. US firm Palantir has provided Kyiv with artificial intelligence-powered tools that sort through gigabytes of data to help commanders understand the war in real time: Russian troop movements, positions and targets. Drone warfare came of age in Ukraine, but now both sides are roughly matched in capabilities, and armies around the world are catching up.
SoK: Anti-Facial Recognition Technology
Wenger, Emily, Shan, Shawn, Zheng, Haitao, Zhao, Ben Y.
The rapid adoption of facial recognition (FR) technology by both government and commercial entities in recent years has raised concerns about civil liberties and privacy. In response, a broad suite of so-called "anti-facial recognition" (AFR) tools has been developed to help users avoid unwanted facial recognition. The set of AFR tools proposed in the last few years is wide-ranging and rapidly evolving, necessitating a step back to consider the broader design space of AFR systems and long-term challenges. This paper aims to fill that gap and provides the first comprehensive analysis of the AFR research landscape. Using the operational stages of FR systems as a starting point, we create a systematic framework for analyzing the benefits and tradeoffs of different AFR approaches. We then consider both technical and social challenges facing AFR tools and propose directions for future research in this field.
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., Giménez-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.