pwc-archive/papers-with-abstracts huggingface dataset:
Bayesian interpolation for power laws in neural data analysis
Authors: Iván A. Davidovich, Yasser Roudi
Date: 2022-04-18 00:00:00

Power laws arise in a variety of phenomena ranging from matter undergoing phase transition to the distribution of word frequencies in the English language. Usually, their presence is only apparent when data is abundant, and accurately determining their exponents often requires even larger amounts of data. As the scale of recordings in neuroscience becomes larger, an increasing number of studies attempt to characterise potential power-law relationships in neural data. In this paper, we aim to discuss the potential pitfalls that one faces in such efforts and to promote a Bayesian interpolation framework for this purpose. We apply this framework to synthetic data and to data from a recent study of large-scale recordings in mouse primary visual cortex (V1), where the exponent of a power-law scaling in the data played an important role: its value was argued to determine whether the population's stimulus-response relationship is smooth, and experimental data was provided to confirm that this is indeed so. Our analysis shows that with such data types and sizes as we consider here, the best-fit values found for the parameters of the power law and the uncertainty for these estimates are heavily dependent on the noise model assumed for the estimation, the range of the data chosen, and (with all other things being equal) the particular recordings. It is thus challenging to offer a reliable statement about the exponents of the power law. Our analysis, however, shows that this does not affect the conclusions regarding the smoothness of the population response to low-dimensional stimuli but casts doubt on those to natural images. We discuss the implications of this result for the neural code in the V1 and offer the approach discussed here as a framework that future studies, perhaps exploring larger ranges of data, can employ as their starting point to examine power-law scalings in neural data.
Calibrating distribution models from PELVE
Authors: Hirbod Assa, Liyuan Lin, Ruodu Wang
Date: 2022-04-19 00:00:00

The Value-at-Risk (VaR) and the Expected Shortfall (ES) are the two most popular risk measures in banking and insurance regulation. To bridge between the two regulatory risk measures, the Probability Equivalent Level of VaR-ES (PELVE) was recently proposed to convert a level of VaR to that of ES. It is straightforward to compute the value of PELVE for a given distribution model. In this paper, we study the converse problem of PELVE calibration, that is, to find a distribution model that yields a given PELVE, which may either be obtained from data or from expert opinion. We discuss separately the cases when one-point, two-point, n-point and curve constraints are given. In the most complicated case of a curve constraint, we convert the calibration problem to that of an advanced differential equation. We apply the model calibration techniques to estimation and simulation for datasets used in insurance. We further study some technical properties of PELVE by offering a few new results on monotonicity and convergence.
Feature Structure Distillation with Centered Kernel Alignment in BERT Transferring
Authors: Hee-Jun Jung, Doyeon Kim, Seung-Hoon Na, Kangil Kim
Date: 2022-04-01 00:00:00
Tasks: Knowledge Distillation, Language Modeling, Language Modelling

Knowledge distillation is an approach to transfer information on representations from a teacher to a student by reducing their difference. A challenge of this approach is to reduce the flexibility of the student's representations inducing inaccurate learning of the teacher's knowledge. To resolve it in transferring, we investigate distillation of structures of representations specified to three types: intra-feature, local inter-feature, global inter-feature structures. To transfer them, we introduce feature structure distillation methods based on the Centered Kernel Alignment, which assigns a consistent value to similar features structures and reveals more informative relations. In particular, a memory-augmented transfer method with clustering is implemented for the global structures. The methods are empirically analyzed on the nine tasks for language understanding of the GLUE dataset with Bidirectional Encoder Representations from Transformers (BERT), which is a representative neural language model. In the results, the proposed methods effectively transfer the three types of structures and improve performance compared to state-of-the-art distillation methods. Indeed, the code for the methods is available in https://github.com/maroo-sky/FSD.
A Novel Region Duplication Detection Algorithm Based on Hybrid Approach
Authors: Kshipra Tatkare, Manoj Devare
Date: 2022-04-10 00:00:00

The digital images from various sources are ubiquitous due to easy availability of high bandwidth Internet. Digital images are easy to tamper with good or bad intentions. Non-availability of pre-embedded information in digital images makes the tampering detection process more difficult in case of digital forensics. Thus, passive image tampering is difficult to detect. There are various algorithms available for detecting image tampering. However, these algorithms have some drawbacks, due to which all types of tampering cannot be detected. In this paper researchers intend to present the types of image tampering and its detection techniques with example based approach. This paper also illustrates insights into the various existing algorithms and tries to find out efficient algorithm out of them.
Comparative analysis of machine learning and numerical modeling for combined heat transfer in Polymethylmethacrylate
Authors: Mahsa Dehghan Manshadi, Nima Alafchi, Alireza Taat, Milad Mousavi, Amir Mosavi
Date: 2022-04-12 00:00:00

This study compares different methods to predict the simultaneous effects of conductive and radiative heat transfer in a Polymethylmethacrylate (PMMA) sample. PMMA is a kind of polymer utilized in various sensors and actuator devices. One-dimensional combined heat transfer is considered in numerical analysis. Computer implementation was obtained for the numerical solution of governing equation with the implicit finite difference method in the case of discretization. Kirchhoff transformation was used to get data from a non-linear equation of conductive heat transfer by considering monochromatic radiation intensity and temperature conditions applied to the PMMA sample boundaries. For Deep Neural Network (DNN) method, the novel Long Short Term Memory (LSTM) method was introduced to find accurate results in the least processing time than the numerical method. A recent study derived the combined heat transfers and their temperature profiles for the PMMA sample. Furthermore, the transient temperature profile is validated by another study. A comparison proves a perfect agreement. It shows the temperature gradient in the primary positions that makes a spectral amount of conductive heat transfer from a PMMA sample. It is more straightforward when they are compared with the novel DNN method. Results demonstrate that this artificial intelligence method is accurate and fast in predicting problems. By analyzing the results from the numerical solution it can be understood that the conductive and radiative heat flux is similar in the case of gradient behavior, but it is also twice in its amount approximately. Hence, total heat flux has a constant value in an approximated steady state condition. In addition to analyzing their composition, ROC curve and confusion matrix were implemented to evaluate the algorithm performance.
A multi-stream deep neural network with late fuzzy fusion for real-world anomaly detection
Authors: Kamalakar Vijay Thakare, Nitin Sharma, Debi Prosad Dogra, Heeseung Choi, Ig-JaeKim
Date: 2022-03-27 00:00:00
Proceeding: Expert Systems with Applications 2022 3
Tasks: Abnormal Event Detection In Video, Anomaly Detection, Anomaly Detection In Surveillance Videos, Event Detection, Multiple Instance Learning, Outlier Detection, Video Anomaly Detection

Abnormal event detection in video is alternatively known as outlier detection, where machine learning can be highly effective. While testing an unknown video, the objective of such methods is to verify the video’s category, e.g. normal or abnormal. This paper exploits visual information from normal as well as abnormal videos to train a deep multiple instance learning classifier for classification of videos. Existing multiple instance learning classifiers presume that the training videos contain only short-duration anomalous events. This assumption may not be valid for all real-world anomalies. Also, multiple occurrences of anomalies in training videos cannot be ruled out. This paper shows that by injecting temporal information in feature extraction, anomaly detection performance can be improved. To accomplish this, two spatio-temporal deep feature extractors have been applied in parallel on the training videos. These streams are then used to train a modified multiple instance learning-based classifier. Finally, a fuzzy aggregation is employed to fuse the anomaly scores. Additionally, two lightweight deep-learning classifiers have been used to substantiate the model’s efficacy for classifying fire and accident events. To understand the reliability and performance of the proposed method, extensive experiments have been carried out using UCF-Crime video dataset containing 13 anomaly categories. The dataset has been restructured into five broad categories based on the severity of actions to study the robustness of the proposed method. The paper provides sufficient empirical evidence which proves that by incorporating temporal features in the pipeline, anomaly detection accuracy can be significantly improved. Moreover, the model helps to detect long-duration anomalies in videos, which was not possible using existing methods. The proposed end-to-end multi-stream architecture performs abnormal event detection with accuracy as high as 84.48%, which is better than the performance of existing video anomaly detection methods. Moreover, the class-wise detection accuracy has improved by 6%–14% across various broad categories.
Multi-Camera Multiple 3D Object Tracking on the Move for Autonomous Vehicles
Authors: Pha Nguyen, Kha Gia Quach, Chi Nhan Duong, Ngan Le, Xuan-Bac Nguyen, Khoa Luu
Date: 2022-04-19 00:00:00
Tasks: 3D Object Detection, 3D Object Tracking, Autonomous Vehicles, Link Prediction, Object, object-detection, Object Detection, Object Tracking

The development of autonomous vehicles provides an opportunity to have a complete set of camera sensors capturing the environment around the car. Thus, it is important for object detection and tracking to address new challenges, such as achieving consistent results across views of cameras. To address these challenges, this work presents a new Global Association Graph Model with Link Prediction approach to predict existing tracklets location and link detections with tracklets via cross-attention motion modeling and appearance re-identification. This approach aims at solving issues caused by inconsistent 3D object detection. Moreover, our model exploits to improve the detection accuracy of a standard 3D object detector in the nuScenes detection challenge. The experimental results on the nuScenes dataset demonstrate the benefits of the proposed method to produce SOTA performance on the existing vision-based tracking dataset.
Photometric space object classification via deep learning algorithms
Authors: Tong Liu, K. Ulrich Schreiber ∗
Date: 2021-05-08 00:00:00
Proceeding: Acta Astronautica 2021 5
Tasks: Classification, Classification with Binary Neural Network, Deep Learning, Object

Accurate time transfer by time of flight measurements via diffuse reflections on passive orbiting space debris targets requires a selection of suitable objects out of a large catalogue of debris items. In this paper, we report on our development of an automatic classification system of space objects based on photometric observations of sun illuminated satellite and debris items from the Mini–Mega TORTORA (MMT) system observation data base by a deep learning algorithm. A deep neural network model based on a convolutional long short-term memory network has been designed to identify four different object categories with a test accuracy of over 85%. The method is also suitable for an automated analysis of the temporal evolution of the orbit motion of specific space objects.
Sound-Guided Semantic Video Generation
Authors: Seung Hyun Lee, Gyeongrok Oh, Wonmin Byeon, Chanyoung Kim, Won Jeong Ryoo, Sang Ho Yoon, Hyunjun Cho, Jihyun Bae, Jinkyu Kim, Sangpil Kim
Date: 2022-04-20 00:00:00
Tasks: Video Editing, Video Generation

The recent success in StyleGAN demonstrates that pre-trained StyleGAN latent space is useful for realistic video generation. However, the generated motion in the video is usually not semantically meaningful due to the difficulty of determining the direction and magnitude in the StyleGAN latent space. In this paper, we propose a framework to generate realistic videos by leveraging multimodal (sound-image-text) embedding space. As sound provides the temporal contexts of the scene, our framework learns to generate a video that is semantically consistent with sound. First, our sound inversion module maps the audio directly into the StyleGAN latent space. We then incorporate the CLIP-based multimodal embedding space to further provide the audio-visual relationships. Finally, the proposed frame generator learns to find the trajectory in the latent space which is coherent with the corresponding sound and generates a video in a hierarchical manner. We provide the new high-resolution landscape video dataset (audio-visual pair) for the sound-guided video generation task. The experiments show that our model outperforms the state-of-the-art methods in terms of video quality. We further show several applications including image and video editing to verify the effectiveness of our method.
Demonstration of Superconducting Optoelectronic Single-Photon Synapses
Authors: Saeed Khan, Bryce A. Primavera, Jeff Chiles, Adam N. McCaughan, Sonia M. Buckley, Alexander N. Tait, Adriana Lita, John Biesecker, Anna Fox, David Olaya, Richard P. Mirin, Sae Woo Nam, Jeffrey M. Shainline
Date: 2022-04-20 00:00:00

Superconducting optoelectronic hardware is being explored as a path towards artificial spiking neural networks with unprecedented scales of complexity and computational ability. Such hardware combines integrated-photonic components for few-photon, light-speed communication with superconducting circuits for fast, energy-efficient computation. Monolithic integration of superconducting and photonic devices is necessary for the scaling of this technology. In the present work, superconducting-nanowire single-photon detectors are monolithically integrated with Josephson junctions for the first time, enabling the realization of superconducting optoelectronic synapses. We present circuits that perform analog weighting and temporal leaky integration of single-photon presynaptic signals. Synaptic weighting is implemented in the electronic domain so that binary, single-photon communication can be maintained. Records of recent synaptic activity are locally stored as current in superconducting loops. Dendritic and neuronal nonlinearities are implemented with a second stage of Josephson circuitry. The hardware presents great design flexibility, with demonstrated synaptic time constants spanning four orders of magnitude (hundreds of nanoseconds to milliseconds). The synapses are responsive to presynaptic spike rates exceeding 10 MHz and consume approximately 33 aJ of dynamic power per synapse event before accounting for cooling. In addition to neuromorphic hardware, these circuits introduce new avenues towards realizing large-scale single-photon-detector arrays for diverse imaging, sensing, and quantum communication applications.
Assembly Planning from Observations under Physical Constraints
Authors: Thomas Chabal, Robin Strudel, Etienne Arlaud, Jean Ponce, Cordelia Schmid
Date: 2022-04-20 00:00:00
Tasks: Object, object-detection, Object Detection, Pose Estimation

This paper addresses the problem of copying an unknown assembly of primitives with known shape and appearance using information extracted from a single photograph by an off-the-shelf procedure for object detection and pose estimation. The proposed algorithm uses a simple combination of physical stability constraints, convex optimization and Monte Carlo tree search to plan assemblies as sequences of pick-and-place operations represented by STRIPS operators. It is efficient and, most importantly, robust to the errors in object detection and pose estimation unavoidable in any real robotic system. The proposed approach is demonstrated with thorough experiments on a UR5 manipulator.
Comparing Deep Reinforcement Learning Algorithms in Two-Echelon Supply Chains
Authors: Francesco Stranieri, Fabio Stella
Date: 2022-04-20 00:00:00
Tasks: Decision Making, Deep Reinforcement Learning, Management, reinforcement-learning, Reinforcement Learning, Reinforcement Learning (RL), Sequential Decision Making

In this study, we analyze and compare the performance of state-of-the-art deep reinforcement learning algorithms for solving the supply chain inventory management problem. This complex sequential decision-making problem consists of determining the optimal quantity of products to be produced and shipped across different warehouses over a given time horizon. In particular, we present a mathematical formulation of a two-echelon supply chain environment with stochastic and seasonal demand, which allows managing an arbitrary number of warehouses and product types. Through a rich set of numerical experiments, we compare the performance of different deep reinforcement learning algorithms under various supply chain structures, topologies, demands, capacities, and costs. The results of the experimental plan indicate that deep reinforcement learning algorithms outperform traditional inventory management strategies, such as the static (s, Q)-policy. Furthermore, this study provides detailed insight into the design and development of an open-source software library that provides a customizable environment for solving the supply chain inventory management problem using a wide range of data-driven approaches.
Generalizing to the Future: Mitigating Entity Bias in Fake News Detection
Authors: Yongchun Zhu, Qiang Sheng, Juan Cao, Shuokai Li, Danding Wang, Fuzhen Zhuang
Date: 2022-04-20 00:00:00
Tasks: Fake News Detection

The wide dissemination of fake news is increasingly threatening both individuals and society. Fake news detection aims to train a model on the past news and detect fake news of the future. Though great efforts have been made, existing fake news detection methods overlooked the unintended entity bias in the real-world data, which seriously influences models' generalization ability to future data. For example, 97\% of news pieces in 2010-2017 containing the entity `Donald Trump' are real in our data, but the percentage falls down to merely 33\% in 2018. This would lead the model trained on the former set to hardly generalize to the latter, as it tends to predict news pieces about `Donald Trump' as real for lower training loss. In this paper, we propose an entity debiasing framework (\textbf{ENDEF}) which generalizes fake news detection models to the future data by mitigating entity bias from a cause-effect perspective. Based on the causal graph among entities, news contents, and news veracity, we separately model the contribution of each cause (entities and contents) during training. In the inference stage, we remove the direct effect of the entities to mitigate entity bias. Extensive offline experiments on the English and Chinese datasets demonstrate that the proposed framework can largely improve the performance of base fake news detectors, and online tests verify its superiority in practice. To the best of our knowledge, this is the first work to explicitly improve the generalization ability of fake news detection models to the future data. The code has been released at https://github.com/ICTMCG/ENDEF-SIGIR2022.
SiamHAN: IPv6 Address Correlation Attacks on TLS Encrypted Traffic via Siamese Heterogeneous Graph Attention Network
Authors: Tianyu Cui, Gaopeng Gou, Gang Xiong, Zhen Li, Mingxin Cui, Chang Liu
Date: 2022-04-20 00:00:00
Tasks: Graph Attention

Unlike IPv4 addresses, which are typically masked by a NAT, IPv6 addresses could easily be correlated with user activity, endangering their privacy. Mitigations to address this privacy concern have been deployed, making existing approaches for address-to-user correlation unreliable. This work demonstrates that an adversary could still correlate IPv6 addresses with users accurately, even with these protection mechanisms. To do this, we propose an IPv6 address correlation model - SiamHAN. The model uses a Siamese Heterogeneous Graph Attention Network to measure whether two IPv6 client addresses belong to the same user even if the user's traffic is protected by TLS encryption. Using a large real-world dataset, we show that, for the tasks of tracking target users and discovering unique users, the state-of-the-art techniques could achieve only 85% and 60% accuracy, respectively. However, SiamHAN exhibits 99% and 88% accuracy.
Quantity vs Quality: Investigating the Trade-Off between Sample Size and Label Reliability
Authors: Timo Bertram, Johannes Fürnkranz, Martin Müller
Date: 2022-04-20 00:00:00

In this paper, we study learning in probabilistic domains where the learner may receive incorrect labels but can improve the reliability of labels by repeatedly sampling them. In such a setting, one faces the problem of whether the fixed budget for obtaining training examples should rather be used for obtaining all different examples or for improving the label quality of a smaller number of examples by re-sampling their labels. We motivate this problem in an application to compare the strength of poker hands where the training signal depends on the hidden community cards, and then study it in depth in an artificial setting where we insert controlled noise levels into the MNIST database. Our results show that with increasing levels of noise, resampling previous examples becomes increasingly more important than obtaining new examples, as classifier performance deteriorates when the number of incorrect labels is too high. In addition, we propose two different validation strategies; switching from lower to higher validations over the course of training and using chi-square statistics to approximate the confidence in obtained labels.