pwc-archive/papers-with-abstracts huggingface dataset:
When can weak latent factors be statistically inferred?
Authors: Jianqing Fan, Yuling Yan, Yuheng Zheng
Date: 2024-07-04 00:00:00

This article establishes a new and comprehensive estimation and inference theory for principal component analysis (PCA) under the weak factor model that allow for cross-sectional dependent idiosyncratic components under the nearly minimal factor strength relative to the noise level or signal-to-noise ratio. Our theory is applicable regardless of the relative growth rate between the cross-sectional dimension $N$ and temporal dimension $T$. This more realistic assumption and noticeable result require completely new technical device, as the commonly-used leave-one-out trick is no longer applicable to the case with cross-sectional dependence. Another notable advancement of our theory is on PCA inference $ - $ for example, under the regime where $N\asymp T$, we show that the asymptotic normality for the PCA-based estimator holds as long as the signal-to-noise ratio (SNR) grows faster than a polynomial rate of $\log N$. This finding significantly surpasses prior work that required a polynomial rate of $N$. Our theory is entirely non-asymptotic, offering finite-sample characterizations for both the estimation error and the uncertainty level of statistical inference. A notable technical innovation is our closed-form first-order approximation of PCA-based estimator, which paves the way for various statistical tests. Furthermore, we apply our theories to design easy-to-implement statistics for validating whether given factors fall in the linear spans of unknown latent factors, testing structural breaks in the factor loadings for an individual unit, checking whether two units have the same risk exposures, and constructing confidence intervals for systematic risks. Our empirical studies uncover insightful correlations between our test results and economic cycles.
Continuous Optimization for Offline Change Point Detection and Estimation
Authors: Hans Reimann, Sarat Moka, Georgy Sofronov
Date: 2024-07-03 00:00:00
Tasks: Change Point Detection

This work explores use of novel advances in best subset selection for regression modelling via continuous optimization for offline change point detection and estimation in univariate Gaussian data sequences. The approach exploits reformulating the normal mean multiple change point model into a regularized statistical inverse problem enforcing sparsity. After introducing the problem statement, criteria and previous investigations via Lasso-regularization, the recently developed framework of continuous optimization for best subset selection (COMBSS) is briefly introduced and related to the problem at hand. Supervised and unsupervised perspectives are explored with the latter testing different approaches for the choice of regularization penalty parameters via the discrepancy principle and a confidence bound. The main result is an adaptation and evaluation of the COMBSS approach for offline normal mean multiple change-point detection via experimental results on simulated data for different choices of regularisation parameters. Results and future directions are discussed.
missForestPredict -- Missing data imputation for prediction settings
Authors: Elena Albu, Shan Gao, Laure Wynants, Ben van Calster
Date: 2024-07-02 00:00:00
Tasks: Imputation, Prediction

Prediction models are used to predict an outcome based on input variables. Missing data in input variables often occurs at model development and at prediction time. The missForestPredict R package proposes an adaptation of the missForest imputation algorithm that is fast, user-friendly and tailored for prediction settings. The algorithm iteratively imputes variables using random forests until a convergence criterion (unified for continuous and categorical variables and based on the out-of-bag error) is met. The imputation models are saved for each variable and iteration and can be applied later to new observations at prediction time. The missForestPredict package offers extended error monitoring, control over variables used in the imputation and custom initialization. This allows users to tailor the imputation to their specific needs. The missForestPredict algorithm is compared to mean/mode imputation, linear regression imputation, mice, k-nearest neighbours, bagging, miceRanger and IterativeImputer on eight simulated datasets with simulated missingness (48 scenarios) and eight large public datasets using different prediction models. missForestPredict provides competitive results in prediction settings within short computation times.
Optimizing Nepali PDF Extraction: A Comparative Study of Parser and OCR Technologies
Authors: Prabin Paudel, Supriya Khadka, Ranju G. C., Rahul Shah
Date: 2024-07-05 00:00:00
Tasks: Optical Character Recognition, Optical Character Recognition (OCR)

This research compares PDF parsing and Optical Character Recognition (OCR) methods for extracting Nepali content from PDFs. PDF parsing offers fast and accurate extraction but faces challenges with non-Unicode Nepali fonts. OCR, specifically PyTesseract, overcomes these challenges, providing versatility for both digital and scanned PDFs. The study reveals that while PDF parsers are faster, their accuracy fluctuates based on PDF types. In contrast, OCRs, with a focus on PyTesseract, demonstrate consistent accuracy at the expense of slightly longer extraction times. Considering the project's emphasis on Nepali PDFs, PyTesseract emerges as the most suitable library, balancing extraction speed and accuracy.
An Interactive Multi-modal Query Answering System with Retrieval-Augmented Large Language Models
Authors: Mengzhao Wang, Haotian Wu, Xiangyu Ke, Yunjun Gao, Xiaoliang Xu, Lu Chen
Date: 2024-07-05 00:00:00
Tasks: Answer Generation, Contrastive Learning, Retrieval

Retrieval-augmented Large Language Models (LLMs) have reshaped traditional query-answering systems, offering unparalleled user experiences. However, existing retrieval techniques often struggle to handle multi-modal query contexts. In this paper, we present an interactive Multi-modal Query Answering (MQA) system, empowered by our newly developed multi-modal retrieval framework and navigation graph index, integrated with cutting-edge LLMs. It comprises five core components: Data Preprocessing, Vector Representation, Index Construction, Query Execution, and Answer Generation, all orchestrated by a dedicated coordinator to ensure smooth data flow from input to answer generation. One notable aspect of MQA is its utilization of contrastive learning to assess the significance of different modalities, facilitating precise measurement of multi-modal information similarity. Furthermore, the system achieves efficient retrieval through our advanced navigation graph index, refined using computational pruning techniques. Another highlight of our system is its pluggable processing framework, allowing seamless integration of embedding models, graph indexes, and LLMs. This flexibility provides users diverse options for gaining insights from their multi-modal knowledge base. A preliminary video introduction of MQA is available at https://youtu.be/xvUuo2ZIqWk.
Leveraging Topic Specificity and Social Relationships for Expert Finding in Community Question Answering Platforms
Authors: Maddalena Amendola, Andrea Passarella, Raffaele Perego
Date: 2024-07-04 00:00:00
Tasks: Community Question Answering, Learning-To-Rank, Question Answering, Specificity

Online Community Question Answering (CQA) platforms have become indispensable tools for users seeking expert solutions to their technical queries. The effectiveness of these platforms relies on their ability to identify and direct questions to the most knowledgeable users within the community, a process known as Expert Finding (EF). EF accuracy is crucial for increasing user engagement and the reliability of provided answers. Despite recent advancements in EF methodologies, blending the diverse information sources available on CQA platforms for effective expert identification remains challenging. In this paper, we present TUEF, a Topic-oriented User-Interaction model for Expert Finding, which aims to fully and transparently leverage the heterogeneous information available within online question-answering communities. TUEF integrates content and social data by constructing a multi-layer graph that maps out user relationships based on their answering patterns on specific topics. By combining these sources of information, TUEF identifies the most relevant and knowledgeable users for any given question and ranks them using learning-to-rank techniques. Our findings indicate that TUEF's topic-oriented model significantly enhances performance, particularly in large communities discussing well-defined topics. Additionally, we show that the interpretable learning-to-rank algorithm integrated into TUEF offers transparency and explainability with minimal performance trade-offs. The exhaustive experiments conducted on six different CQA communities of Stack Exchange show that TUEF outperforms all competitors with a minimum performance boost of 42.42% in P@1, 32.73% in NDCG@3, 21.76% in R@5, and 29.81% in MRR, excelling in both the evaluation approaches present in the previous literature.
Reviewers of Educational Immersive and Extended Reality (XR) experiences: Who is creating these reviews and why?
Authors: Sophie McKenzie, Shaun Bangay, Maria Nicholas, Adam Cardilini, Majeet Singh
Date: 2024-07-04 00:00:00
Tasks: Mixed Reality

This paper presents a scoping review of literature to examine who is reviewing educational immersive or extended reality - eduXR experiences and why. EduXR experiences in augmented, virtual or mixed reality take many forms, from supporting manual training, engaging learners in conservation, to provide opportunities for social connection. For users of eduXR, reviews of an experience can provide information that helps them determine whether it will meet their learning needs or not. The source of the review, that is, who they are and why they have conducted the review, is critical in helping the user judge the reviews quality and relevance. At present, there is no settled review system in place for eduXR, though relevant frameworks exist for serious games review with relevance and overlap for some, but not all, eduXR experiences. While some authors have engaged in preparing a detailed review structure for eduXR, there remains a need for a clear and simple way for users of eduXR to know details about reviewers, e.g., who and why, to help make it easier for users to identify relevant reviews and gain useful insight about eduXR experiences. To help address this issue, we conducted a scoping review asking the question; Who is creating eduXR reviews, and why? We identified 16 papers that present an academic evaluation on the review process of eduXR reviews. The 16 papers were analysed, coding for who themes and why themes over two separate cycles, using thematic analysis. An analysis looked to examine what we know regarding who is providing the reviews, and why, to help us to understand what enables, inhibits and what is yet unknown about how the eduXR community goes about making informed choices regarding the eduXR experiences they engage with.
Deep Pareto Reinforcement Learning for Multi-Objective Recommender Systems
Authors: Pan Li, Alexander Tuzhilin
Date: 2024-07-04 00:00:00
Tasks: Recommendation Systems, reinforcement-learning, Reinforcement Learning

Optimizing multiple objectives simultaneously is an important task for recommendation platforms to improve their performance. However, this task is particularly challenging since the relationships between different objectives are heterogeneous across different consumers and dynamically fluctuating according to different contexts. Especially in those cases when objectives become conflicting with each other, the result of recommendations will form a pareto-frontier, where the improvements of any objective comes at the cost of a performance decrease of another objective. Existing multi-objective recommender systems do not systematically consider such dynamic relationships; instead, they balance between these objectives in a static and uniform manner, resulting in only suboptimal multi-objective recommendation performance. In this paper, we propose a Deep Pareto Reinforcement Learning (DeepPRL) approach, where we (1) comprehensively model the complex relationships between multiple objectives in recommendations; (2) effectively capture personalized and contextual consumer preference for each objective to provide better recommendations; (3) optimize both the short-term and the long-term performance of multi-objective recommendations. As a result, our method achieves significant pareto-dominance over the state-of-the-art baselines in the offline experiments. Furthermore, we conducted a controlled experiment at the video streaming platform of Alibaba, where our method simultaneously improved three conflicting business objectives over the latest production system significantly, demonstrating its tangible economic impact in practice.
When LLM Meets Hypergraph: A Sociological Analysis on Personality via Online Social Networks
Authors: Zhiyao Shu, Xiangguo Sun, Hong Cheng
Date: 2024-07-04 00:00:00

Individual personalities significantly influence our perceptions, decisions, and social interactions, which is particularly crucial for gaining insights into human behavior patterns in online social network analysis. Many psychological studies have observed that personalities are strongly reflected in their social behaviors and social environments. In light of these problems, this paper proposes a sociological analysis framework for one's personality in an environment-based view instead of individual-level data mining. Specifically, to comprehensively understand an individual's behavior from low-quality records, we leverage the powerful associative ability of LLMs by designing an effective prompt. In this way, LLMs can integrate various scattered information with their external knowledge to generate higher-quality profiles, which can significantly improve the personality analysis performance. To explore the interactive mechanism behind the users and their online environments, we design an effective hypergraph neural network where the hypergraph nodes are users and the hyperedges in the hypergraph are social environments. We offer a useful dataset with user profile data, personality traits, and several detected environments from the real-world social platform. To the best of our knowledge, this is the first network-based dataset containing both hypergraph structure and social information, which could push forward future research in this area further. By employing the framework on this dataset, we can effectively capture the nuances of individual personalities and their online behaviors, leading to a deeper understanding of human interactions in the digital world.
A Neural Named Entity Recognition and Multi-Type Normalization Tool for Biomedical Text Mining
Authors: Donghyeon Kim, Jinhyuk Lee, Chan Ho So, Hwisang Jeon, Minbyul Jeong, Yonghwa Choi, Wonjin Yoon, Mujeen Sung, Jaewoo Kang
Date: 2019-06-04 00:00:00
Proceeding: IEEE Access 2019 6
Tasks: Articles, Information Retrieval, named-entity-recognition, Named Entity Recognition, Named Entity Recognition (NER), Question Answering, Relation Extraction

The amount of biomedical literature is vast and growing quickly, and accurate text mining techniques could help researchers to efficiently extract useful information from the literature. However, existing named entity recognition models used by text mining tools such as tmTool and ezTag are not effective enough, and cannot accurately discover new entities. Also, the traditional text mining tools do not consider overlapping entities, which are frequently observed in multi-type named entity recognition results. We propose a neural biomedical named entity recognition and multi-type normalization tool called BERN. The BERN uses high-performance BioBERT named entity recognition models which recognize known entities and discover new entities. Also, probability-based decision rules are developed to identify the types of overlapping entities. Furthermore, various named entity normalization models are integrated into BERN for assigning a distinct identifier to each recognized entity. The BERN provides a Web service for tagging entities in PubMed articles or raw text. Researchers can use the BERN Web service for their text mining tasks, such as new named entity discovery, information retrieval, question answering, and relation extraction. The application programming interfaces and demonstrations of BERN are publicly available at https://bern.korea.ac.kr
Conditional Consistency Regularization for Semi-Supervised Multi-label Image Classification
Authors: Zhengning Wu; Tianyu He; Xiaobo Xia; Jun Yu; Xu Shen; Tongliang Liu
Date: 2023-10-21 00:00:00
Proceeding: journal 2023 10
Tasks: Classification, image-classification, Image Classification, Multi-Label Image Classification

Consistency regularization has achieved great successes in Semi-Supervised Single-Label Image Classification (SS-SLC) with deep learning models, while few effort has been devoted to Semi-Supervised Multi-Label Image Classification (SS-MLC) with deep learning models. One intuitive solution for introducing consistency regularization to SS-MLC is to regularize model predictions to be invariant to different augmented data of the same input image. However, the solution lacks the consideration of label relations, which are key elements in multi-label image classification. In this article, we go beyond the consistency regularization for multi-view input images, and propose Conditional Consistency Regularization (CCR) that is tailored for SS-MLC. Specifically, for two augmented input images, we make the two model predictions conditioned on different label states (i.e., positive, negative, or unknown for each class). By encouraging the two predictions to be consistent, the model is able to build relations between the given two different label states, which helps to make use of label relations for boosting image classification. The experiments on large-scale real-world SS-MLC benchmarks demonstrate that the proposed method can surpass state-of-the-art methods by a large margin.
A Randomized Approach to Probabilistic Footprint Estimation of a Space Debris Uncontrolled Reentry
Authors: Alessandro Falsone and Maria Prandini
Date: 2017-01-14 00:00:00
Proceeding: IEEE 2017 1
Tasks: Position

This paper studies the problem of characterizing
the region of the airspace that will be occupied by a space debris
during an uncontrolled reentry (footprint), with the final goal
of supporting the air traffic controllers in their task of guiding
aircraft safely from their origin to their destination. Given the
various sources of uncertainty affecting the debris dynamics,
the reentry process is characterized probabilistically and the
problem of determining the footprint is formulated in terms of a
chance-constrained optimization program, which is solved via a
simulation-based method. When observations of the debris initial
position and radar measurements of the aircraft prior to the
reentry event are available, nonlinear filtering techniques can be
adopted and the posterior probability distribution of the debris
position as well as of the wind field affecting the reentry process
can be integrated in the chance-constraint formulation so as to
obtain an enhanced estimate of the footprint. Simulation results
show the efficacy of the approach.
Medical Image Fusion for High-Level Analysis: A Mutual Enhancement Framework for Unaligned PAT and MRI
Authors: Yutian Zhong, Jinchuan He, Zhichao Liang, Shuangyang Zhang, Qianjin Feng, Lijun Lu, Li Qi
Date: 2024-07-04 00:00:00
Tasks: Anatomy, Image Generation, Instance Segmentation, Medical Image Analysis, Semantic Segmentation, Style Transfer

Photoacoustic tomography (PAT) offers optical contrast, whereas magnetic resonance imaging (MRI) excels in imaging soft tissue and organ anatomy. The fusion of PAT with MRI holds promising application prospects due to their complementary advantages. Existing image fusion have made considerable progress in pre-registered images, yet spatial deformations are difficult to avoid in medical imaging scenarios. More importantly, current algorithms focus on visual quality and statistical metrics, thus overlooking the requirements of high-level tasks. To address these challenges, we propose an unsupervised fusion model, termed PAMRFuse+, which integrates image generation and registration. Specifically, a cross-modal style transfer network is introduced to simplify cross-modal registration to single-modal registration. Subsequently, a multi-level registration network is employed to predict displacement vector fields. Furthermore, a dual-branch feature decomposition fusion network is proposed to address the challenges of cross-modal feature modeling and decomposition by integrating modality-specific and modality-shared features. PAMRFuse+ achieves satisfactory results in registering and fusing unaligned PAT-MRI datasets. Moreover, for the first time, we evaluate the performance of medical image fusion with multi-organ instance segmentation. Extensive experimental demonstrations reveal the advantages of PAMRFuse+ in improving the performance of medical image analysis tasks.
PianoBART: Symbolic Piano Music Generation and Understanding with Large-Scale Pre-Training
Authors: Xiao Liang, Zijian Zhao, Weichao Zeng, Yutong He, Fupeng He, Yiyi Wang, Chengying Gao
Date: 2024-06-26 00:00:00
Tasks: Music Generation

Learning musical structures and composition patterns is necessary for both music generation and understanding, but current methods do not make uniform use of learned features to generate and comprehend music simultaneously. In this paper, we propose PianoBART, a pre-trained model that uses BART for both symbolic piano music generation and understanding. We devise a multi-level object selection strategy for different pre-training tasks of PianoBART, which can prevent information leakage or loss and enhance learning ability. The musical semantics captured in pre-training are fine-tuned for music generation and understanding tasks. Experiments demonstrate that PianoBART efficiently learns musical patterns and achieves outstanding performance in generating high-quality coherent pieces and comprehending music. Our code and supplementary material are available at https://github.com/RS2002/PianoBart.
A federated graph neural network framework for privacy-preserving personalization
Authors: Chuhan Wu, Fangzhao Wu, Lingjuan Lyu, Tao Qi, Yongfeng Huang, Xing Xie
Date: 2022-06-02 00:00:00
Proceeding: Nature Communications 2022 6
Tasks: Federated Learning, Graph Neural Network, Privacy Preserving, Recommendation Systems

Graph neural network (GNN) is effective in modeling high-order interactions and has been widely used in various personalized applications such as recommendation. However, mainstream personalization methods rely on centralized GNN learning on global graphs, which have considerable privacy risks due to the privacy-sensitive nature of user data. Here, we present a federated GNN framework named FedPerGNN for both effective and privacy-preserving personalization. Through a privacy-preserving model update method, we can collaboratively train GNN models based on decentralized graphs inferred from local data. To further exploit graph information beyond local interactions, we introduce a privacy-preserving graph expansion protocol to incorporate high-order information under privacy protection. Experimental results on six datasets for personalization in different scenarios show that FedPerGNN achieves 4.0% ~ 9.6% lower errors than the state-of-the-art federated personalization methods under good privacy protection. FedPerGNN provides a promising direction to mining decentralized graph data in a privacy-preserving manner for responsible and intelligent personalization.