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Rolling bearing fault feature selection based on standard deviation and random forest classifier using vibration signals

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ADVANCES IN MECHANICAL ENGINEERING 2023年第4期15卷

作者： Imane, Moussaoui Rahmoune, Chemseddine Benazzouz, Djamel Univ Mhamed Bougara Solid Mech & Syst Lab LMSS Boumerdes Algeria Univ Mhamed Bougara Fac Technol Solid Mech & Syst Lab LMSS Boumerdes 35000 Algeria

The precise identification of faults is vital for ensuring the reliability of the bearing's performance, and thus, the functionality of rotary machinery. The focus of our study is on the role that feature selection plays in improving the accuracy of predictive models used for diagnosis. The study combined the Standard Deviation (STD) parameter with the Random Forest (RF) classifier to select relevant features from vibration signals obtained from bearings operating under various conditions. We utilized three databases with different bearings' health states operating under distinct conditions. The results of the study were promising, indicating that the proposed method was not only effective but also consistent, even under time-varying conditions.

关键词： Feature selection standard deviation random forest optimization algorithm bearing fault diagnosis

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An optimal algorithm for mmWave 5G wireless networks based on neural network

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HELIYON 2023年第6期9卷 e17580页

作者： Chen, Liang Sefat, Shebnam M. Kim, Ki-Il Jilin Prov Inst Educ ChangChun 130022 Peoples R China Independent Univ Dept Comp Sci Dhaka Bangladesh Islamic Univ Islamic Univ Ctr Sci Res Najaf Iraq Chungnam Natl Univ Dept Comp Sci & Engn Daejeon 34134 South Korea

Fifth generation (5G) wireless networks are based on the use of spectrum blocks above 6 GHz in the millimeter wave (mmWave) range to increase throughput and reduce the overall level of interference in very busy frequency bands below 6 GHz. With the global deployment of the first commercial installations of 5G, the availability of multi-Gbps wireless connections in the mmWave frequency band becomes closer to reality and opens up some unique uses for 5G. Although, mmWave communication is expected to enable high-power radio links and broadband wireless intranet, its main challenges are inherent poor propagation conditions and high transmitter-receiver coordination requirement, which prevent it from realizing its full potential. When smart reflective surfaces are used in mmWave communication, channel state information becomes complex and imprecise. In this study, a hybrid intelligent reflecting surface consisting of a large number of passive components and a small number of RF circuits is proposed as a solution. Then, an improved deep neural network (DNN)-based technique is proposed to estimate the effective channel. The proposed technique provides better channel estimation performance according to the simulation results and improves the quality of service.

关键词： mmWave communication 5G networks optimization algorithm Channel estimation

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Intelligent Resource Scheduling Method for Surface Observation of Satellites based on Segmented Coding

Intelligent Resource Scheduling Method for Surface Observati...

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第六届体系工程学术会议—体系工程与高质量发展

作者：俞棋睿尹明娄矫媛媛王笑潘晓刚 College of Science National University of Defense Technology College of Systems Engineering National University of Defense Technology

With the development of modern military strategy, satellite observation has become a key asset for obtaining global security and operational environment dynamics. This article proposes an intelligent scheduling method for ground observation of satellite based on segmented coding, aiming to optimize observation plans, improve the quality and efficiency of data collection. The article first analyzes the current research status of satellite observation duration allocation and points out the shortcomings of current research on ground observation task duration allocation. In response to this issue, this article establishes an observation duration allocation model, which maximizes the observation benefits of satellites in different orbits(high, medium, and low) by adjusting the observation duration decision variables of each satellite. The model introduces an encoding system to represent different observation time allocation schemes and establishes a relationship function between observation duration and benefit value. Furthermore, this article proposes an improved genetic algorithm based on allele replacement to solve the allocation problem of observation time. The experimental results show that the method tends to stabilize after 10000 iterations, and the total allocatable time resource utilization rate of the proposed scheduling scheme reaches 99.9999%, which is much higher than the benefit value of the uniform allocation scheme, proving the feasibility and effectiveness of the proposed method in this paper.

关键词： satellite observation Resource scheduling Observation duration allocation Genetic algorithm optimization algorithm

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LCU-level Rate-Distortion optimization for Versatile Video Coding

LCU-level Rate-Distortion Optimization for Versatile Video C...

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IEEE International Symposium on Circuits and Systems

作者： Gencheng Xu Shiyu Jin KaichenTang Zijing Zhang Yimin Zhou Schoo of Couer Science nd Engineering Universiy of Eecronic Science nd Technoogy of Chin ChengduSchoo of Couer Science nd Engineering Universiy of Eecronic Science nd Technoogy of Chin ChengduSchoo of Couer Science nd Engineering Universiy of Eecronic Science nd Technoogy of Chin ChengduSchoo of Couer Science nd Engineering Universiy of Eecronic Science nd Technoogy of Chin ChengduSchoo of Cybersecuriy Chengdu Universiy of Inforion Technoogy Chengdu

ISBN: (数字)9781665484855

ISBN: (纸本)9781665484862

Rate-distortion curve is greatly influenced by the texture and motion compensation. Therefore, using a uniform Lagrangian multiplier (lambda, to all the LCUs in a picture may not achieve the optimal coding performance. To address the challenging problem on how to formulate the appropriate to an individual LCU, this paper proposes a LCU-level Lagrangian multiplier adaption (LLMA) algorithm. Firstly, a motion compensation information entropy (MCIE) of 16 16 block is calculated by obtaining a simple binary information entropy from the source. Secondly, MCIE is normalized to a standard normal distribution, on the basis of the strong assumption that the video sources obey the Gaussian distribution. Thirdly, an adaption factor is assigned to a LCU, which multiples on the picture-level from the system calculation. Experiments show that the proposed LLMA algorithm achieves remarkable performance in low-delay and random-access configurations, with the resulting achievements of 1.81% BD-Rate gains, compared with VTM 13.0 at low-delay common test condition.

关键词： information entropy motion compensation Lagrangian multiplier optimization algorithm

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Implementation of a steganography system based on hybrid square quaternion moment compression in IoMT

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JOURNAL OF KING SAUD UNIVERSITY-COMPUTER AND INFORMATION SCIENCES 2023年第7期35卷

作者： Tahiri, Mohamed Amine Bencherqui, Ahmed Karmouni, Hicham Amakdouf, Hicham Mirjalili, Seyedali Motahhir, Saad Abouhawwash, Mohamed Askar, S. S. Sayyouri, Mhamed Qjidaa, Hassan Sidi Mohamed Ben Abdellah Fez Univ Dhar El Mahrez Fac Sci Lab Elect Signals & Syst Informat LESSI STICCED ST Fes 30000 Morocco Sidi Mohamed Ben Abdellah Univ Natl Sch Appl Sci Engn Syst & Applicat Lab Fes 30000 Morocco Cadi Ayyad Univ Natl Sch Appl Sci Marrakech 40000 Morocco Sidi Mohamed Ben Abdellah Univ Inst Sports Sci Fes 30000 Morocco Torrens Univ Australia Ctr Artificial Intelligence Res & Optimisat Brisbane Qld 4006 Australia Michigan State Univ Coll Engn Dept Computat Math Sci & Engn CMSE E Lansing MI 48824 USA Mansoura Univ Fac Sci Dept Math Mansoura 35516 Egypt King Saud Univ Coll Sci Dept Stat & Operat Res POB 2455 Riyadh 11451 Saudi Arabia

Internet of Medical Things (IoMT) systems generate medical data transmissions between patients, med-ical experts, and medical centers over public networks, which require high levels of security to protect the content of medical images and the personal information they contain. In this paper, we propose a new stego image encryption scheme based on a new secret image compression method, wavelet trans-formation, QR decomposition of the cover image, and a new chaotic map. The secret image is compressed by the Hahn-Krawtchouk hybrid quaternion square moments (HK-HQSM), which are optimized by a new hybrid metaheuristic algorithm based on the Salp Swarm algorithm (SSA) and the Arithmetic optimization algorithm (AOA). To increase the security level when transmitting the proposed stego im-ages over public networks, we introduce a new chaotic map based on the 2D fractional Henon map to encrypt the stego image. To demonstrate the effectiveness of the proposed steganography scheme for IoMT, we implemented this scheme on a low-cost Raspberry Pi 4 hardware board. The results of the per-formed numerical experiments show that our method is secure and provides exceptional robustness against common standard image processing attacks (steganalysis attacks). The results also demonstrate that our strategy is able to work efficiently and quickly when implemented on a Raspberry Pi board.& COPY;2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY license (http://***/licenses/by/4.0/).

关键词： Index Terms Image steganography Internet of Medical Things Hybrid square moments optimization algorithm Raspberry Pi

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Priority-aware task assignment and path planning for efficient and load-balanced multi-UAV operation

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VEHICULAR COMMUNICATIONS 2023年 42卷

作者： Poudel, Sabitri Moh, Sangman Chosun Univ Dept Comp Engn Gwangju 61452 South Korea

Unmanned aerial vehicles (UAVs) have emerged as a viable option in numerous real-world applications. In large mission planning systems, demanding the effective completion of a wide variety of tasks, multi-UAV systems are significantly preferred. Collaborative task assignment and path planning have a significant impact on autonomous operation of multi-UAV systems. In this study, we propose a priority-aware task assignment and path planning (AMTP) algorithm based on actor-critic multi-agent reinforcement learning for multi-UAV operations. We utilize an actor-critic multi-agent framework based on centralized training and decentralized execution for task assignment and path planning of heterogeneous UAVs. A multi-agent deep deterministic policy gradient framework is used to train the system to deal with both the elements of the dynamic environment and the heterogeneity of UAVs and tasks. The critic network evaluates the policy by maintaining the global network state information and combines the actions of agents to simplify the training state. On the other hand, agents decide which actions to comply with their local observations to improve the policy. The performance evaluation results obtained through simulation show that the proposed AMTP outperforms existing methods in terms of task completion rate, load balancing, energy efficiency, and convergence time. & COPY;2023 Elsevier Inc. All rights reserved.

关键词： Unmanned aerial vehicle Task assignment Path planning optimization algorithm Reinforcement learning Multi-UAV network

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Experimental method for modal parameter identification of civil engineering structures based on improved wavelet transform

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RESULTS IN ENGINEERING 2023年 20卷

作者： He, Ran Li, Hui Tang, Jia Hu, Zhangqi Zhang, Zaihua Hunan City Univ Coll Civil Engn Yiyang 413000 Peoples R China

With the continuous acceleration of the global construction industry, many structural infrastructure structures in China have been put into use for decades. They are very prone to damage due to fatigue. The modal parameter identification of civil engineering construction can evaluate the safety status of infrastructure structures. In view of this, an identification system of civil engineering structure modal parameters is proposed based on improved wavelet transform. In the process, the mode shape was chosen as the method of wavelet transform. The data was discretized by selecting the actual data of a high-speed railway station combined with sensors and wavelet transform. Finally, the correct identification of the modal parameters of civil engineering structures is realized. The data shows that under normal conditions where there is only white noise interference, the waveform of the structure is relatively stable, and the amplitude fluctuation is in the [-2,3] interval. At the same time, the average amplitude of the structure is in the [2.2, -1.5] interval under normal conditions. In addition, the positive and negative extreme points are 3.7 and -2.3, respectively. This indicates that the structure amplitude fluctuation is in a dynamic and stable state under normal circumstances. The optimized wavelet transform method identifies a total of four orders in the first six natural frequencies. The minimum error is 0.11%, the maximum error is 1.50%, and the average error of the first four natural frequencies is 0.578%. In addition, based on the comparison of theoretical and identification values of longitudinal vibration shapes, the proposed method can successfully detect abnormal values at the 10th and 18th nodes. From the above results, it shows that the wavelet transform method has high accuracy and small error in frequency identification. It meets the requirements of identifying the natural frequency parameters of the structure. From the calculation, the method propos

关键词： WT Discretization Modal parameter identification Scale Vibration mode optimization algorithm

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Using a Robot Calibration Approach Toward Fitting a Human Arm Model

Using a Robot Calibration Approach Toward Fitting a Human Ar...

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30th International Conference on Robotics in Alpe-Adria-Danube Region (RAAD)

作者： Cornagliotto, Valerio Digo, Elisa Pastorelli, Stefano Politecn Torino Dept Mech & Aerosp Engn Turin Italy

ISBN: (纸本)9783030752613;9783030752590;9783030752583

In the context of Industry 4.0, the human-robot interaction (HRI) can be improved by tracking the human arm in the workspace shared with the robot. This goal takes advantage of a customized human arm modeling and it should be conveniently achieved with a limited number of sensors and a reduced computational time. In this paper, considering the analogy between human and robotic arms, a new method for the identification of a custom-made human arm model was inspired by a robot calibration process. The Denavit-Hartenberg (DH) parameters of the arm model were estimated recording a suitable number of hand poses. Hence, a robotic arm was exploited to test the new method. To simplify the fitting procedure of a reliable robot model, the minimum number of the necessary end-effector (EE) poses was investigated. Through an optoelectronic system, the EE pose trajectory of a UR3 robot was recorded. The optimization of the DH parameters was repeatedly run decreasing the downsampling frequency of the acquired data and then the trajectory error was evaluated. A new reference dataset of robot configurations was acquired permutating the joints degrees of freedom among values of 0, +90, or -90 degrees. Hence, the method to fit the model considering few EE poses was tested on six robot configurations randomly selected from the dataset. Overall, trajectory errors highlighted the applicability of this method in the context of HRI.

关键词： optimization algorithm Robotic model Human-robot interaction Industry 4.0 Denavit-Hartenberg parameters Optoelectronic system

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Battery energy-storage system: A review of technologies, optimization objectives, constraints, approaches, and outstanding issues

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JOURNAL OF ENERGY STORAGE 2021年 42卷

作者： Hannan, M. A. Wali, S. B. Ker, P. J. Abd Rahman, M. S. Mansor, M. Ramachandaramurthy, V. K. Muttaqi, K. M. Mahlia, T. M. I. Dong, Z. Y. Univ Tenaga Nas Dept Elect Power Engn Kajang 43000 Selangor Malaysia Univ Tenaga Nas Inst Sustainable Energy Kajang 43000 Selangor Malaysia Univ Wollongong Sch Elect Comp & Telecommun Engn Wollongong NSW 2522 Australia Univ Technol Sydney Sch Civil & Environm Engn Ctr Green Technol Sydney NSW 2007 Australia Univ New South Wales Sch Elect Engn & Telecommun Sydney NSW 2052 Australia

Due to urbanization and the rapid growth of population, carbon emission is increasing, which leads to climate change and global warming. With an increased level of fossil fuel burning and scarcity of fossil fuel, the power industry is moving to alternative energy resources such as photovoltaic power (PV), wind power (WP), and battery energy-storage systems (BESS), among others. BESS has some advantages over conventional energy sources, which include fast and steady response, adaptability, controllability, environmental friendliness, and geographical independence, and it is considered as a potential solution to the global warming problem. This paper provides a comprehensive review of the battery energy-storage system concerning optimal sizing objectives, the system constraint, various optimization models, and approaches along with their advantages and weakness. Furthermore, for better understanding, the optimization objectives and methods have been classified into different categories. This paper also provides a detailed discussion on the BESS applications and explores the shortages of existing optimal BESS sizing algorithms to identify the gaps for future research. The issues and challenges are also highlighted to provide a clear idea to the researchers in the field of BESS. Overall, this paper conveys some significant recommendations that would be useful to the researchers and policymakers to structure a productive, powerful, efficient, and robust battery energy-storage system toward a future with a sustainable environment.

关键词： Battery energy-storage system Sizing optimization algorithm Objective functions Constraints

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Shape Adjustment of Large Deployable Mesh Reflectors under Thermal Strain

Shape Adjustment of Large Deployable Mesh Reflectors under T...

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AIAA Science and Technology Forum and Exposition (AIAA SciTech Forum)

作者： Yuan, S. Yang, B. Lawrence Technol Univ A Leon Linton Dept Mech Robot & Ind Engn Southfield MI 48075 USA Univ Southern Calif Dept Aerosp & Mech Engn Los Angeles CA 90089 USA

ISBN: (数字)9781624106095

ISBN: (纸本)9781624106095

Large deployable mesh reflectors are widely used as space antennas for signal transmission purposes. In design of large deployable mesh reflectors, it is crucially important to secure a desired reflecting surface with high accuracy. However, such desired shape is hard to maintain under surface distortions caused by thermal strain. Traditional shape adjustment methods usually require utilization of a large number of actuators, which is a critical issue due to difficulty of fixing malfunctioning actuators and lack of power supply. To solve this problem, a new method for optimal shape adjustment of large deployable mesh reflectors is proposed. In this method, a linear relationship between nodal displacements and undeformed member lengths is firstly established by the singular value decomposition method. Then, locations of actuators are automatically determined by a mixed integer optimization algorithm. Finally, given a shape accuracy requirement, the minimal number of actuators is determined by a try-and-error process. The proposed method is computationally inexpensive since only linear systems are required to be solved. This method can significantly reduce the surface error of a reflector by only using a small number of actuators, which shall be proved in simulation results.

关键词： Actuators optimization algorithm Singular Value Decomposition Power Supplies Space Antenna Elastic Properties Genetic algorithm Smart Materials and Structures Numerical optimization Thermal Expansion

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