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A Neuro-Symbolic Framework for Answering Graph Pattern Queries in Knowledge Graphs

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arXiv 2023年

作者： Cucumides, Tamara Daza, Daniel Barceló, Pablo Cochez, Michael Geerts, Floris Reutter, Juan L. Romero, Miguel Department of Computer Science University of Antwerp Belgium Computer Science Vrije Universiteit Amsterdam Netherlands Discovery Lab Elsevier Amsterdam Netherlands Inst. for Math. and Comp. Eng. Universidad Católica de Chile IMFD Chile CENIA Chile Chile Department of Computer Science Universidad Católica de Chile Chile

The challenge of answering graph queries over incomplete knowledge graphs is gaining significant attention in the machine learning community. Neuro-symbolic models have emerged as a promising approach, combining good performance with high interpretability. These models utilize trained architectures to execute atomic queries and integrate modules that mimic symbolic query operators. However, most neuro-symbolic query processors are constrained to tree-like graph pattern queries. These queries admit a bottom-up execution with constant values or anchors at the leaves and the target variable at the root. While expressive, tree-like queries fail to capture critical properties in knowledge graphs, such as the existence of multiple edges between entities or the presence of triangles. We introduce a framework for answering arbitrary graph pattern queries over incomplete knowledge graphs, encompassing both cyclic queries and tree-like queries with existentially quantified leaves. These classes of queries are vital for practical applications but are beyond the scope of most current neuro-symbolic models. Our approach employs an approximation scheme that facilitates acyclic traversals for cyclic patterns, thereby embedding additional symbolic bias into the query execution process. Our experimental evaluation demonstrates that our framework performs competitively on three datasets, effectively handling cyclic queries through our approximation strategy. Additionally, it maintains the performance of existing neuro-symbolic models on anchored tree-like queries and extends their capabilities to queries with existentially quantified variables. © 2023, CC BY.

关键词： Trees (math.matics)

A Theory of Link Prediction via Relational Weisfeiler-Leman on Knowledge Graphs

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arXiv 2023年

作者： Huang, Xingyue Ceylan, İsmail İlkan Orth, Miguel Romero Barceló, Pablo Department of Computer Science University of Oxford Oxford United Kingdom Department of Computer Science Universidad Católica de Chile CENIA Chile Chile Inst. for Math. and Comp. Eng. Universidad Católica de Chile IMFD Chile CENIA Chile Chile

Graph neural networks are prominent models for representation learning over graph-structured data. While the capabilities and limitations of these models are well-understood for simple graphs, our understanding remains incomplete in the context of knowledge graphs. Our goal is to provide a systematic understanding of the landscape of graph neural networks for knowledge graphs pertaining to the prominent task of link prediction. Our analysis entails a unifying perspective on seemingly unrelated models and unlocks a series of other models. The expressive power of various models is characterized via a corresponding relational Weisfeiler-Leman algorithm. This analysis is extended to provide a precise logical characterization of the class of functions captured by a class of graph neural networks. The theoretical findings presented in this paper explain the benefits of some widely employed practical design choices, which are validated empirically. Copyright © 2023, The Authors. All rights reserved.

关键词： Knowledge graph

Insight into Voting Problem Complexity Using Randomized Classes

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arXiv 2022年

作者： Fitzsimmons, Zack Hemaspaandra, Edith Dept. of Math. and Computer Science College of the Holy Cross WorcesterMA01610 United States Department of Computer Science Rochester Institute of Technology RochesterNY14623 United States

The first step in classifying the complexity of an NP problem is typically showing the problem in P or NP-complete. This has been a successful first step for many problems, including voting problems. However, in this paper we show that this may not always be the best first step. We consider the problem of constructive control by replacing voters (CCRV) introduced by Loreggia et al. (2015) for the scoring rule First-Last, which is defined by (1, 0, ⋯;0, -1). We show that this problem is equivalent to Exact Perfect Bipartite Matching, and so CCRV for First-Last can be determined in random polynomial time. So on the one hand, if CCRV for First-Last is NP-complete then RP = NP, which is extremely unlikely. On the other hand, showing that CCRV for First-Last is in P would also show that Exact Perfect Bipartite Matching is in P, which would solve a well-studied 40-year-old open problem. By considering RP as an option we also gain insight into the complexity of CCRV for 2-Approval, ultimately showing it in P, which settles the complexity of the sole open problem in the comprehensive table from Erdélyi et al. (2021). Copyright © 2022, The Authors. All rights reserved.

关键词： Polynomial approximation

Graph Fourier MMD for Signals on Graphs

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Graph Fourier MMD for Signals on Graphs

2023 International Conference on Sampling Theory and Applications, SampTA 2023

作者： Leone, Samuel Venkat, Aarthi Huguet, Guillaume Tong, Alexander Wolf, Guy Krishnaswamy, Smita Applied Math Program New HavenCT United States Yale University Computational Biology & Bioinformatics Program New HavenCT United States Université de Montréal Mila - Quebec Ai Institute Dept. of Math. & Stat Montreal Canada Université de Montréal Mila-Quebec Ai Institute Dept. of Comp. Sci. & Oper. Res. Montreal Canada Yale University Department of Computer Science Department of Genetics New HavenCT United States

ISBN: (纸本)9798350328851

While numerous methods have been proposed for computing distances between probability distributions in Euclidean space, relatively little attention has been given to computing such distances for distributions on graphs. However, there has been a marked increase in data that either lies on graph (such as protein interaction networks) or can be modeled as a graph (single cell data), particularly in the biomedical sciences. Thus, it becomes important to find ways to compare signals defined on such graphs. Here, we propose Graph Fourier MMD (GFMMD), a novel distance between distributions and signals on graphs. GFMMD is defined via an optimal witness function that is both smooth on the graph and maximizes the difference in expectation between the pair of distributions on the graph. We find an analytical solution to this optimization problem as well as an embedding of distributions that results from this method. We also prove several properties of this method including scale invariance and applicability to disconnected graphs. We showcase it on graph benchmark datasets as well on single cell RNA-sequencing data analysis. In the latter, we use the GFMMD-based gene embeddings to find meaningful gene clusters. We also propose a novel type of score for gene selection called gene localization score which helps select genes for cellular state space characterization. © 2023 IEEE.

关键词： Genes

A New Clustering Approach based on Trust and Rat Swarm Algorithm for WSN Applications

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A New Clustering Approach based on Trust and Rat Swarm Algor...

Advances in Intelligent Computing and Applications (AICAPS), International Conference on

作者： Walid Osamy Ahmed Salim Amel Al Ali Ahmed M. Khedr Computer Science Department Faculty of Computers and Artificial Intelligence Benha University Benha Egypt Math. Department Faculty of Science Zagazig University Zagazig Egypt Department of CS College of Sci. and Arts Al-Methnab Qassim University KSA Dept. of Information Systems Sharjah University Sharjah UAE Dept. of Computer Science Sharjah University Sharjah UAE

In this paper, a clustering approach called CATRSO is proposed. The selection of cluster heads (CH) is performed by considering the trust value of the nodes in order to select the most trustworthy nodes as CH and Rat Swarm Optimizer is employed for CH selection process. The trust value of the nodes and remaining energy are taken into account while designing the fitness function. In addition, a chain routing approach is employed between CHs for energy savings. The results demonstrate that the CATRSO technique is successful in selecting the most trustworthy nodes as CH and outperforms earlier efforts in the literature in terms of energy efficiency, average network lifetime, and trustworthiness of selected CHs.

关键词： Wireless communication Measurement Wireless sensor networks Simulation Clustering algorithms Rats Routing

Numerical and analytical calculations of orbit-wise synthetic spectra from two-step gamma-ray fusion reactions 50

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Numerical and analytical calculations of orbit-wise syntheti...

50th EPS Conference on Plasma Physics, EPS 2024

作者： Valentini, A. Nocente, M. Eriksson, J. Järleblad, H. Moseev, D. Reman, B.C.G. Rud, M. Snicker, A. Stagner, L. Salewski, M. Department of Physics Technical University of Denmark Kgs Lyngby2800 Denmark Department of Physics University of Milano-Bicocca Milan20126 Italy Department of Physics and Astronomy Uppsala University Uppsala75120 Sweden Department of Appl. Math. & Computer Science Technical University of Denmark Kgs Lyngby2800 Denmark Max-Planck-Institut fur Plasmaphysik Wendelsteinstr. 1 Greifswald17491 Germany Laboratory for Plasma Physics LPP-ERM/KMS BrusselsB-1000 Belgium Department of Applied Physics Aalto University AaltoFI-00076 Finland General Atomics P.O. Box 85608 San DiegoCA92186-5609 United States

Provable benefits of actor-critic methods for offline reinforcement learning

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arXiv 2021年

作者： Zanette, Andrea Wainwright, Martin J. Brunskill, Emma Inst. for Comp. and Math. Engineering Department of Statistics EECS Department of Computer Science Stanford University

Actor-critic methods are widely used in offline reinforcement learning practice, but are not so well-understood theoretically. We propose a new offline actor-critic algorithm that naturally incorporates the pessimism principle, leading to several key advantages compared to the state of the art. The algorithm can operate when the Bellman evaluation operator is closed with respect to the action value function of the actor's policies;this is a more general setting than the low-rank MDP model. Despite the added generality, the procedure is computationally tractable as it involves the solution of a sequence of second-order programs. We prove an upper bound on the suboptimality gap of the policy returned by the procedure that depends on the data coverage of any arbitrary, possibly data dependent comparator policy. The achievable guarantee is complemented with a minimax lower bound that is matching up to logarithmic factors. Copyright © 2021, The Authors. All rights reserved.

关键词： Reinforcement learning

Security Analysis of Docker Containers for ARM Architecture

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Security Analysis of Docker Containers for ARM Architecture

IEEE/ACM Symposium on Edge Computing (SEC)

作者： Md Sadun Haq Ali Şaman Tosun Turgay Korkmaz Department of Computer Science University Of Texas At San Antonio San Antonio USA Dept. of Math. and Comp. Sci University Of North Carolina at Pembroke Pembroke USA

ISBN: (数字)9781665486118

ISBN: (纸本)9781665486125

Containers provide a better performance, faster deployment than virtual machines and provide near-native performance, with isolation and security drawbacks. Although the security of containers for the Intel architecture has been investigated in more detail, there is limited work on the security of containers for the ARM architecture. In this paper, we address this gap in research and focus on the security of containers designed for the ARM architecture, which is heavily used in IoT devices. Edge computing offers many advantages, including reduced latency and resource requirements at the cloud because data can be processed at the edge before it is sent to the cloud. Using containers at the edge nodes of IoT-Edge-Cloud systems can enhance such advantages at the cost of increasing security vulnerabilities in such systems. Therefore, it is essential to investigate the security of containers designed for the ARM architecture. Accordingly, we obtained official ARM images from DockerHub and used various security tools to scan these ARM images. We found that 72% of all the vulnerabilities show varying severity levels and each tool seems to work best for particular base images. We investigated how each tool detects sub-packages and achieves a different hit ratio while none of them alone can detect at least 80% of all the vulnerabilities. In addition, we also investigated how the Docker images and their vulnerability landscape change over a period of six months by running the scanning tools twice. Finally, we also conducted a dynamic analysis of some of the images on the Raspberry Pi and study their effects. We believe this paper will facilitate the use of ARM containers at the ARM-based edge nodes by addressing security issues.

关键词： Cloud computing Program processors Image edge detection computer architecture Containers Virtual machining Libraries

Power-fractional distributions and branching processes

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arXiv 2025年

作者： Alsmeyer, Gerold Hoang, Viet Hung Inst. Math. Stochastics Department of Mathematics and Computer Science University of Münster Orléans-Ring 10 MünsterD-48149 Germany Faculty of Fundamental Science Industrial University of Ho Chi Minh City No. 12 Nguyen Van Bao Ward 4 Go Vap District Ho Chi Minh City Viet Nam

In branching process theory, linear-fractional distributions are commonly used to model individual reproduction, especially when the goal is to obtain more explicit formulas than those derived under general model assumptions. In this article, we explore a generalization of these distributions, first introduced by Sagitov and Lindo, which offers similar advantages. We refer to these as power-fractional distributions, primarily because, as we demonstrate, they exhibit power-law behavior. Along with a discussion of their additional properties, we present several results related to the Galton-Watson branching process in both constant and randomly varying environments, illustrating these advantages. The use of power-fractional distributions in continuous time, particularly within the framework of Markov branching processes, is also briefly *** Codes Primary 60J80, Secondary 60K37, 60H25 © 2025, CC BY.

关键词： Markov chains