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A Non Local Feature-Preserving Strategy for Image Denoising

Chinese Journal of Electronics 2023年第4期21卷 651-656页

作者： Ning HE Ke LU School of Information Beijing Union University Beijing China College of Computing and Communication Engineering Graduate University of Chinese Academy of Sciences Beijing China

In this paper, we propose a variational image denoising model by exploiting an adaptive feature-preserving strategy which is derived from the Non-local means (NL-means) denoising approach. The commonly used NL-means filter is not optimal for noisy images containing small features of interest since image noise always makes it difficult to estimate the correct coefficients for averaging, leading to over-smoothing and other artifacts. We address this problem by a non-local detail preserving constraint, which is performed by adding two terms in the Total variation (TV) model. One is a non local patch based regularization term that controls the amount of denoising to preserve textures, small details, or global information, the other is a new data fidelity term, which forces the gradients of desired image being close to the smoothed normal. The Euler-Lagrange equation is used to solve the problem. Experimental results show that the proposed method can alleviate the over-smoothing effect and other artifacts, while preserving the fine details.

关键词： TV Image edge detection Noise reduction Force Information security approximation algorithms Mathematical models

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Equivalent Field Stress Level and Usage with Multiple Distributional Stress Types

Equivalent Field Stress Level and Usage with Multiple Distri...

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Annual Symposium on Reliability and Maintainability (RAMS)

作者： Jiliang Zhang Rivian Automotive Palo Alto CA USA

ISBN: (数字)9798350367744

ISBN: (纸本)9798350367751

With one multi-variable acceleration model family, which is commonly used in real world practice, the distributional stress condition and distributional usage are converted to single-valued equivalent stress condition and single-valued equivalent usage, respectively. The derived single-valued equivalent stress condition is exact solution without approximation. The algorithm with approximation for single-valued equivalent stress condition in more general situations is also discussed. The equivalent usage is derived independently from the stress. These results significantly simplify the reliability analysis of the products subject to the random loading conditions with multiple stress types. The applications in reliability validation test and reliability prediction are discussed.

关键词： Loading Random access memory approximation algorithms Reliability Stress Load modeling

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Deep Learning Based Enhanced Approximate Message Passing for mmWave Massive MIMO Channel Estimation

Deep Learning Based Enhanced Approximate Message Passing for...

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International Conference on Signal Processing and Communication (ICSC)

作者： Anusaya Swain Athira K Shrishail M. Hiremath Sarat Kumar Patra Department of Electronics and Communication National Institute of Technology Rourkela Odisha

ISBN: (数字)9798331511890

ISBN: (纸本)9798331511906

This paper presents a new approach to channel estimation in millimeter-wave beamspace massive MIMO systems. The proposed method is an approximate message passing algorithm that utilizes a flexible discriminative denoiser. The denoiser consists of two parts: a noise level map identifier and a convolutional neural network. By learning the channel structure and estimating the noise characteristics, the denoiser enhances the performance of the message passing algorithm. Simulation results demonstrate that the proposed network outperforms networks using DnCNN denoisers and existing compressed sensing-based algorithms.

关键词： Deep learning Message passing Simulation Channel estimation Signal processing algorithms Massive MIMO approximation algorithms Millimeter wave communication Signal to noise ratio Antenna arrays

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Exploration of Crop Planting Strategies Based on Simulated Annealing Algorithm and VIF Tests

Exploration of Crop Planting Strategies Based on Simulated A...

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Electronics, Energy Systems and Power Engineering (EESPE), IEEE International Conference on

作者： Yuyan Liu Xinyi Li Yuzhou Chu Rui Jiang Yu Gan Xiangtan University Xiangtan China

ISBN: (数字)9798350389579

ISBN: (纸本)9798350389586

The aim of this paper is to explore the planting strategy based on simulated annealing algorithm and VIF test by analyzing the planting decision in order to achieve the efficient use of resources and sustainable development of green industry. The study first assumed the ratio of total planted crop production to expected sales in 2023, and constructed a multiobjective planning model using the planting of different types of plots from 2024 to 2030 as decision variables. The improved simulated annealing algorithm solves the model through the outer-point penalty function method and the centered log-ratio transformation to derive the expected returns under the two sales strategies and analyze the sensitivity and stability of the model. In addition, this paper establishes a stochastic planning model based on the consideration of potential risks, and applies the sampling approximate average method to solve the model to further optimize the planting strategy. The problem of multicollinearity among crops was verified through the VIF test, and ridge regression was utilized to improve the interpretability of the model. Ultimately, the results of the study showed an increase in expected returns under different cropping strategies and suggested feasible cropping improvements. This study provides a practical theoretical basis for agricultural decisionmaking, which is of great significance for improving agricultural productivity and promoting sustainable development.

关键词： Analytical models Adaptation models Sensitivity Crops Stochastic processes Simulated annealing approximation algorithms Stability analysis Planning Sustainable development

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Research on the Application System of Multi-Objective Optimization Algorithm in the Allocation of Educational Resources in Colleges and Universities

Research on the Application System of Multi-Objective Optimi...

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Cybersecurity, Internet of Things and Soft Computing (CITSC), Asia-Europe Conference on

作者： Feng Qian Lei Zhang School of Mathematics and Computer Science Tongling University Tongling China

ISBN: (数字)9798331504205

ISBN: (纸本)9798331504212

This article examines the application system of multi-objective optimization algorithm in resource allocation, to enhance the fairness and efficiency of resource allocation. Resource allocation encompasses multiple objectives, such as maximizing resource utilization, minimizing costs and guaranteeing fairness, thus it is extremely crucial to construct a rational optimization model. This paper first designs a resource allocation algorithm based on multi-objective optimization, combining the weight allocation method and the Pareto optimal solution to adapt to the diversified needs of resources. Then a simulation platform is constructed to simulate the actual resource allocation scenario through the operation of the algorithm, and the allocation results are accurately analyzed. The experimental outcomes demonstrate that the algorithm can effectively enhance the efficiency and fairness of resource allocation within different resource limitations. In comparison with the traditional allocation approach, the resource utilization ratio is raised by over 15%, the cost is decreased by approximately 10%, and the fairness index is notably optimized. This system not only provides a reference for the reasonable allocation of resources, but also lays the foundation for the dynamic optimization of resource allocation.

关键词： Costs Supply and demand Heuristic algorithms Optimization models Pareto optimization approximation algorithms Dynamic scheduling Resource management Internet of Things Optimization

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A Matching-Based Algorithm for the Traveling Tournament Problem 39

A Matching-Based Algorithm for the Traveling Tournament Prob...

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39th Annual AAAI Conference on Artificial Intelligence, AAAI 2025

作者： Zhao, Jingyang Xiao, Mingyu University of Electronic Science and Technology of China China

ISBN: (纸本)157735897X

The Traveling Tournament Problem (TTP-k) is a well-known benchmark problem in tournament timetabling. It involves designing a feasible double round-robin tournament for a sports league of n teams under several feasibility requirements, while minimizing the total traveling costs of the teams. The parameter k requires that in the tournament at most k consecutive home games or away games for each team are allowed. TTP-k with a small k, especially for k = 2, 3 and 4, have been extensively studied in the literature. In this paper, we focus on TTP-4 and design an efficient algorithm for it based on minimum weight matching. In theory, we prove that our algorithm has an approximation ratio of 1.625 + Ε for any constant Ε > 0, improving the best-known approximation ratio of 1.7 + Ε. In practice, our experimental results indicate an average improvement of 6.65% over the best-known solutions on 9 benchmark instances. Copyright © 2025, Association for the Advancement of Artificial Intelligence (***). All rights reserved.

关键词： approximation algorithms

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The Complexity of Landmark Hub Labeling 14th

The Complexity of Landmark Hub Labeling

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14th International Conference on algorithms and Complexity, CIAC 2025

作者： Coste, Louann Li, Ruoying Storandt, Sabine Töpfer, Tobias École Normale Supérieure de Lyon Lyon France University of Konstanz Konstanz Germany

ISBN: (纸本)9783031929342

To speed up the computation of shortest path distances between pairs of query nodes in a weighted graph, it is common to precompute a distance oracle. One of the most successful of these oracles is Hub Labeling (HL). Its good practical performance spurred research on the complexity of different HL variants, their structural properties, and suitable construction algorithms. Landmark Hub Labeling (LHL) is a generalization of HL. It enables the construction of distance oracles with similar query time but smaller space consumption than HL, which is an important aspect for practical usability. However, the complexity of LHL has not been thoroughly investigated so far. In this paper, we provide a complete picture of the complexity landscape of different LHL variants. Surprisingly, the only known HL variant for which a minimum-size oracle can be computed in polynomial time (namely ranked hierarchical HL) turns out to be NP-hard when generalized to LHL. We complement our hardness results with suitable approximation algorithms for all studied LHL variants based on novel structural insights. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.

关键词： approximation algorithms

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Frequency Estimation in Data Streams: Learning the Optimal Hashing Scheme (Extended Abstract)

Frequency Estimation in Data Streams: Learning the Optimal H...

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38th IEEE International Conference on Data Engineering (ICDE)

作者： Bertsimas, Dimitris Digalakis, Vassilis, Jr. MIT Cambridge MA 02139 USA

ISBN: (数字)9781665408837

ISBN: (纸本)9781665408837

We present a novel approach for the problem of frequency estimation in data streams that is based on optimization and machine learning. Contrary to state-of-the-art streaming frequency estimation algorithms, which heavily rely on random hashing to maintain the frequency distribution of the data steam using limited storage, the proposed approach exploits an observed stream prefix to near-optimally hash elements and compress the target frequency distribution. We develop and solve (exactly and approximately) an optimization formulation, which enables us to compute optimal or near-optimal hashing schemes for elements seen in the observed stream prefix;then, we use machine learning to hash unseen elements. We empirically evaluate the proposed approach both on synthetic datasets and on real-world search query data. We show that the proposed approach outperforms existing approaches by one to two orders of magnitude in terms of its average (per element) estimation error and by 45-90% in terms of its expected magnitude of estimation error.

关键词： Estimation error Machine learning algorithms Conferences Machine learning Data engineering approximation algorithms Frequency estimation

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Group Formation algorithms

Group Formation Algorithms

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International Carpathian Control Conference (ICCC)

作者： Andrea Mojžišová Marcela Pavlíčková Institute of Control and Informatization of Production Processes Faculty of BERG Technical University of Košice Košice Slovakia

ISBN: (数字)9798331501273

ISBN: (纸本)9798331501280

Sharing knowledge among students, their mutual collaboration, communication, and responsibility for a common goal are skills that are developed through students’ group work on a project or lesson. These skills are important not only for personal growth but also for professional development. One of the key tasks for the effective implementation of group work in education is the formation of groups. This article examines most used algorithms for group formation and select suitable algorithm for our courses.

关键词： Ant colony optimization Metaheuristics Education Bibliometrics Clustering algorithms Collaboration approximation algorithms Particle swarm optimization Genetic algorithms

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Electromagnetic Transient Calculation of Distribution Network System Based on Lie Series-Padé Algorithm

Electromagnetic Transient Calculation of Distribution Networ...

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Advances in Electrical, Electronics and Computing Technology (EECT), International Conference on

作者： Shengjie Zhang Qinggang Meng Yunshuai Zhang Xuewei Gong Xinhui Ji Zibo Power Supply Company State Grid Shandong Electric Power Company Zibo China

ISBN: (数字)9798331541545

ISBN: (纸本)9798331541552

With the expansion of the scale and complexity of the distribution network, the electromechanical transient simulation of the distribution network based on the traditional quasi-steady state assumption can no longer meet the current demand, and more accurate electromagnetic transient simulation calculation is needed. In order to improve the efficiency of electromagnetic transient simulation for large-scale distribution system, a new method based on the Lie Series-Padé algorithm is proposed in this paper. Firstly, the electromagnetic transient model of distribution system is established, including transformer electromagnetic transient model, distribution line electromagnetic transient model and induction motor electromagnetic transient model considering connection mode. Then, a numerical algorithm based on Lie Series-Padé approximation is proposed, which has the advantages of high precision, strong stability and explicit format, and is more suitable for large-scale electromagnetic transient simulation than the traditional implicit ladder method. Finally, a framework for electromagnetic transient simulation of distribution network system based on Lie Series-Padé algorithm is constructed, and a practical distribution network example is used to compare the proposed algorithm with the simulation results of PSCAD to verify the effectiveness of the proposed algorithm.

关键词： Couplings Fuses Distribution networks approximation algorithms Stability analysis Numerical models Computational efficiency Matrix decomposition Thermal stability Numerical stability

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