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Simulation, measurement and optimization of sound absorption in gradient impedance fiber-based composites

MEASUREMENT 2023年第1期221卷

作者： Chen, Jiahao Li, Huiqin Yan, Zonghuan Zhang, Zhichao Gong, Jixian Guo, Yufan Zhang, Jianfei Tiangong Univ Sch Text Sci & Engn Tianjin 300387 Peoples R China Tiangong Univ Key Lab Adv Text Composites Educ Minist Minist Educ Tianjin 300387 Peoples R China Tiangong Univ Sch Comp Sci & Technol Tianjin 300387 Peoples R China Natl Innovat Ctr Adv Dyeing & Finishing Technol Tai An 271000 Peoples R China

In order to achieve effective noise absorption by finite thickness fiber-based materials, fiber-based composites integrating porous, resonant and damping structures were prepared in this research. Here, the effects of gradient structure, number of constituent units, nonwovens thickness and micro-perforated membrane fabric (MPMF) arrangement on the noise reduction of the composites were simulated and measured. The results showed that the gradient fiber-based composite has excellent broadband sound absorption effect. Moreover, designing the arrangement of micro-perforated structures in the composite can further improve its noise reduction coefficient (NRC). The fiber-based composite (thickness of 1.34 cm) designed by the algorithm has an NRC of 0.51, which is much higher than other noise reduction products with the same thickness. The multi-layer fiber-based composites have the advantages of strong noise reduction capability, small thickness, simple processing and low manufacturing cost, which can be flexibly applied in various noise reduction fields.

关键词： Fiber-based composites Gradient impedance Noise reduction Structure design algorithm optimization

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The effect of overabundant projection directions on 3D reconstruction algorithms

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JOURNAL OF STRUCTURAL BIOLOGY 2001年第2-3期133卷 108-118页

作者： Sorzano, COS Marabini, R Boisset, N Rietzel, E Schröder, R Herman, GT Carazo, JM Univ Autonoma Madrid CSIC Ctr Nacl Biotecnol E-28049 Madrid Spain Temple Univ Ctr Comp Sci & Appl Math Philadelphia PA 19122 USA Max Planck Inst Med Forsch D-69120 Heidelberg Germany Univ Paris 06 Equipte Syst Mol & Biol Struct Lab Mineral Cristallog F-75252 Paris 05 France

The experimental process of collecting images from macromolecules in an electron microscope is such that it does not allow for prior specification of the angular distribution of the projection images. As a consequence, an uneven distribution of projection directions may occur. Concerns have been raised recently about the behavior of 3D reconstruction algorithms for the case of unevenly distributed projections. It has been illustrated on experimental data that in the case of a heavily uneven distribution of projection directions some algorithms tend to elongate the reconstructed volumes along the overloaded direction so much as to make a quantitative biological analysis impossible. In answer to these concerns we have developed a strategy for quantitative comparison and optimization of 3D reconstruction algorithms. We apply this strategy to quantitatively analyze algebraic reconstruction techniques (ART) with blobs, simultaneous iterative reconstruction techniques (SIRT) with voxels, and weighted backprojection (WBP). We show that the elongation artifacts that had been previously reported can be strongly reduced. With our specific choices for the free parameters of the three algorithms, NMP reconstructions tend to be inferior to those obtained with either SIRT or ART and the results obtained with ART are comparable to those with SIRT, but at a very small fraction of the computational cost of SIRT. (C) 2001 Academic Press.

关键词： 3D reconstruction algorithms algorithm optimization algorithm comparison collection geometry

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Reducing Search Space of Genetic algorithms for Fast Black Box Attacks on Image Classifiers 1

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42nd German Conference on Artificial Intelligence (KI)

作者： Brandl, Julius Breinl, Nicolas Demmler, Maximilian Hartmann, Lukas Haehner, Joerg Stein, Anthony Univ Augsburg Organ Comp Grp Augsburg Germany

ISBN: (数字)9783030301798

ISBN: (纸本)9783030301798;9783030301781

Recent research regarding the reliability of Deep Neural Networks (DNN) revealed that it is easy to produce images that are completely unrecognizable to humans, but DNNs recognize as classifiable objects with 99.99% confidence. The present study investigates the effect of search space reduction for Genetic algorithms (GA) on their capability of purposefully fooling DNNs. Therefore, we introduce a GA with respective modifications that is able to fool neural networks trained to classify objects from well-known benchmark image data sets like GTSRB or MNIST. The developed GA is extended and thus capable of reducing the search space without changing its general behavior. Empirical results on MNIST indicate a significantly decreased number of generations needed to satisfy the targeted confidence of an MNIST image classifier (12 instead of 228 generations). Conducted experiments on GTSRB, a more challenging object classification scenario, show similar results. Therefore, fooling DNNs has found not only easily possible but can also be done very fast. Our study thus substantiates an already recognized, potential danger for DNN-based computer vision or object recognition applications.

关键词： Genetic algorithm Fooling DNN Search space reduction Black box attack algorithm optimization MNIST GTSRB

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An Optimized Back Propagation Neural Network Based on Genetic algorithm for Line Loss Calculation in Low-voltage Distribution Grid

An Optimized Back Propagation Neural Network Based on Geneti...

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Chinese Automation Congress (CAC)

作者： Guo, Fei Zhang, Lin Liu, Xin Chongqing Univ Posts & Telecommun Chongqing Key Lab Complex Syst & Bion Control Chongqing Peoples R China

ISBN: (纸本)9781728176871

A calculation model of the theoretical line loss rate of smart distribution network in the low-voltage substation area was devised. Based on the hack propagation neural network, the model was optimized by the genetic algorithm (GA-BP model). The model took the active and reactive power of each power supply area as the input and the theoretical line loss rate as the output. The results showed that the genetic algorithm had achieved the best fitness after 92 iterations, and the R-squared of all training data was R=0.99916;after calculated the test samples, the maximum absolute error was 0.14% of GA-BP model, which was 0.61% less than that of the BP model;the mean absolute error was 0.055%, which was 0.273% less than that of BP model. In general, the GA-BP model has a better non-linear fitting ability and higher accuracy of calculating the theoretical line loss rate in the low-voltage distribution area.

关键词： Back propagation neural networks genetic algorithms smart distribution grid algorithm optimization line loss

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Use of a genetic algorithm to assess relative motion in highly elliptic orbits

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JOURNAL OF THE ASTRONAUTICAL SCIENCES 2007年第3期55卷 293-309页

作者： Olsen, Carrie A. Fowler, Wallace T. Mississippi State Univ Mississippi State MS 39762 USA Univ Texas Austin Dept Aerosp Engn & Engn Mech Austin TX 78712 USA NASA Marchall Space Flilght Ctr Washington DC 20546 USA

This paper examines final rendezvous between two vehicles in highly elliptic orbits. The range of eccentricities addressed is 0.6 to 0.9. Due to the varying orbital speeds of the two vehicles, the relative motion during elliptic rendezvous is highly dependent on initial conditions and differs significantly from the relative motion seen in circular rendezvous. The character of the motion has important implications for operational and safety considerations. The development of relative motion targeting and propagation procedures that output relative coordinates in a suitable curvilinear coordinate system is discussed. These procedures are subsequently combined with a genetic algorithm optimization that is used to globally characterize the solution space. Results of genetic algorithm studies are presented and a fuel-optimal family of solutions is identified for further study and characterization.

关键词： algorithm optimization character motion relative motion eccentricities optimal solution Relative coordinates rendezvous Genetic algorithm (GA)

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Annealing-behaved 100-Digit challenge problem optimization

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Procedia Computer Science 2021年 187卷 592-600页

作者： Chenglong Wei Gai-Ge Wang Information Science and Engineering Ocean University of China Qingdao China

In this paper, we optimized PSO by quantum behavior and optimized KH by simulated annealing, so a new hybrid algorithm, named Annealing Krill Quantum Particle Swarm optimization algorithm (AKQPSO), is proposed, and it is based on annealing krill herd algorithm (AKH) and quantum particle swarm optimization algorithm (QPSO). QPSO has better performance in exploitation and AKH has better performance in exploration, so AKQPSO proposed on this basis increases the diversity of population individuals, and shows better performance in both exploitation and exploration. In addition, the quantum behavior increased the diversity of the population, and the simulated annealing strategy made the algorithm avoid falling into the local optimal value, which made the algorithm obtain better performance. The test set used in this paper is a classic 100-Digit Challenge problem, which is proposed at 2019 IEEE Congress on Evolutionary Computation (CEC 2019), and AKQPSO has achieved better performance on the benchmark problems.

关键词： Swarm intelligence annealing-behaved quantum-behaved algorithm optimization

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Optimum Dynamic Navigation Ratio for Launch Vehicles Using Genetic algorithm

Optimum Dynamic Navigation Ratio for Launch Vehicles Using G...

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IEEE Aerospace Conference

作者： Ibrahim, Talaat Zakaria, Mohamed Abdin, Hesham Hafez, Alaa El-Din Sayed Alecxandria Univ Fac Engn Alexandria Egypt Univ Alexandria Fac Engn Alexandria Egypt

ISBN: (纸本)9781479916221

This paper is devoted to demonstrate a Genetic algorithm optimization of a dynamic navigation ratio for launch vehicles target scenario. This optimization provides a bounded target interception under six degrees of freedom control and minimum-effort-miss distance to improve the intercepting accuracy of launch vehicles. This optimization is performed for two guidance laws, the proportional navigation and the differential geometry under influence of target heading, altitude and target maneuvering capabilities. The results show that the optimized dynamic navigation ratio achieves a significant improvement for the miss distance over the previous fixed navigation ratio. The maximum achieved improvement factor is 22 dB for the proportional navigation guidance and 21 dB for the differential geometry.

关键词： launch vehicle Differential Geometry Genetic algorithm (GA) PROPORTIONAL NAVIGATION navigation improvement factor six degrees of freedom algorithm optimization

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Mera: Memory Reduction and Acceleration for Quantum Circuit Simulation via Redundancy Exploration 42

Mera: Memory Reduction and Acceleration for Quantum Circuit ...

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42nd International Conference on Computer Design

作者： Song, Yuhong Sha, Edwin Hsing-Mean Xu, Longshan Zhu, Qingfeng Shao, Zili East China Normal Univ Sch Comp Sci & Technol Shanghai 200062 Peoples R China Chinese Univ Hong Kong Dept Comp Sci & Engn Hong Kong Peoples R China

ISBN: (纸本)9798350380415;9798350380408

With the development of quantum computing, quantum processor demonstrates the potential supremacy in specific applications, such as Grover's database search and popular quantum neural networks (QNNs). For better calibrating the quantum algorithms and machines, quantum circuit simulation on classical computers becomes crucial. However, as the number of quantum bits (qubits) increases, the memory requirement grows exponentially. In order to reduce memory usage and accelerate simulation, we propose a multi-level optimization, namely Mera, by exploring memory and computation redundancy. First, for a large number of sparse quantum gates, we propose two compressed structures for low-level full-state simulation. The corresponding gate operations are designed for practical implementations, which are relieved from the longtime compression and decompression. Second, for the dense Hadamard gate, which is definitely used to construct the superposition, we design a customized structure for significant memory saving as a regularity-oriented simulation. Meanwhile, an ondemand amplitude updating process is optimized for execution acceleration. Experiments show that our compressed structures increase the number of qubits from 17 to 35, and achieve up to 6.9x acceleration for QNN.

关键词： Quantum circuit simulation memory reduction acceleration redundancy exploration algorithm optimization

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Research on Intelligent Recognition algorithms for Common Subgrade Diseases Based on Radar Images 14th

Research on Intelligent Recognition Algorithms for Common Su...

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14th Congress of the International-Association-for-Engineering-Geology-and-the-Environment (IAEG)

作者： Bai, Mingzhou Qi, Yanli Li, Jiazhi Li, Zelin Song, Linlin Dai, Lingkang Tian, Gang Beijing Jiaotong Univ Tangshan Res Inst Tangshan 063000 Peoples R China Beijing Jiaotong Univ Sch Civil Engn Beijing 100044 Peoples R China C E Ctr Engn Res Test & Appraisal Co Ltd Beijing 100142 Peoples R China

ISBN: (纸本)9789819990634;9789819990610;9789819990603

China's operational roadbed diseases show a growing trend in terms of both diversity and quantity, leading to an increasing frequency of road safety accidents caused by these diseases. It is of significant importance to identify the location, morphology, and developmental degree of hidden roadbed diseases and address them accordingly for the safe operation and maintenance of highways during their operational period. Current non-destructive testing methods such as ground-penetrating radar heavily rely on subjective experience for data processing and interpretation, which no longer meet the growing demand for precise and rapid identification of disasters in roadbed engineering. In this study, we established a training set and a test set using images of common roadbed diseases, specifically roadbed looseness and roadbed voids, in a 1:4 ratio, and labeled the disease types in each image. We improved the Faster R-CNN algorithm and obtained two enhanced versions, namely faster_rcnn_inception_v2 and faster_rcnn_resnet50. Both algorithms were trained and indicators such as loss value, test recognition area, and accuracy were analyzed. The results showed that the faster_rcnn_inception_v2 algorithm outperformed the faster_rcnn_resnet50 algorithm with a total loss value of 0.0235, a total of 425 recognized regions, and an accuracy of 91.1% for region recognition. Therefore, the faster_rcnn_inception_v2 algorithm is chosen for the image detection and recognition of roadbed diseases in urban roads.

关键词： Subgrade diseases Radar images Faster R-CNN algorithm algorithm optimization Intelligent recognition

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Efficient Autonomous Navigation in Dynamic Environments: algorithm Evaluation and Multi-Robot Coordination

Efficient Autonomous Navigation in Dynamic Environments: Alg...

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IEEE International Conference on Automatic Control and Intelligent Systems (I2CACIS)

作者： Safir, Mohammed S. M. Wahab, Norhaliza Abdul Mahmud, Mohd Saiful Azimi Alqaraghuli, Hasan Samsuria, Erlianasha Romdlony, Muhammad Zakiyullah Univ Teknol Malaysia Fac Elect Engn Johor Baharu Johor Malaysia Telkom Univ Sch Elect Engn Kabupaten Bandung Jawa Barat Indonesia

ISBN: (纸本)9798350372113;9798350372106

Navigating indoor mobile robots in dynamic environments poses significant challenges due to obstacles and uncharted terrain. This study explores autonomous navigation systems within a laboratory-scale Flexible Manufacturing System (FMS), addressing the need for more reliable and real-time navigation. Objectives include designing a 2D map using SLAM, creating an autonomous indoor navigation system with real-time obstacle avoidance, and establishing a multi-robot navigation framework. Performance of A*, D*, TEB, and DWA algorithms is evaluated in single and multi-robot scenarios. Findings highlight A*'s effectiveness in static environments, D*'s adaptability in dynamic settings, and TEB's superiority in obstacle avoidance over DWA. The study concludes by discussing the potential of A* and TEB in multi-robot applications and suggests future research in algorithm optimization and multi-robot coordination.

关键词： 2D map design algorithm optimization Autonomous navigation systems Multi-robot coordination SLAM (Simultaneous Localization and Mapping)

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