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Articles 28681 - 28710 of 196383

Full-Text Articles in Engineering

Mitigating Inaudible Ultrasound Attacks On Voice Assistants With Acoustic Metamaterials, Joshua S. Lloyd, Cole G. Ludwikowski, Cyrus Malik, Chen Shen Apr 2023

Mitigating Inaudible Ultrasound Attacks On Voice Assistants With Acoustic Metamaterials, Joshua S. Lloyd, Cole G. Ludwikowski, Cyrus Malik, Chen Shen

Henry M. Rowan College of Engineering Departmental Research

Voice assistants play an important role in facilitating human–machine interactions and have been widely used in audio consumer electronic products. However, it has been shown that they are susceptible to inaudible attacks in which the malicious signals are in the ultrasound regime and cannot be heard by human ears. In this study, we show that a judiciously designed acoustic metamaterial filter can mitigate such attacks by modulating the received signals by the microphones. The metamaterial filter is composed of rigid plates with individual holes which exhibit local resonance phenomena that suppress incoming waves at specific frequencies. The effectiveness of the …

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Dynamic Target Assignment Of Multiple Unmanned Aerial Vehicles Based On Clustering Of Network Nodes, Tuo Zhao, Hanqiang Deng, Jialong Gao, Jian Huang Apr 2023

Dynamic Target Assignment Of Multiple Unmanned Aerial Vehicles Based On Clustering Of Network Nodes, Tuo Zhao, Hanqiang Deng, Jialong Gao, Jian Huang

Journal of System Simulation

Abstract: In order to solve the problem that the distributed multi-UAV target assignment algorithm is prone to communication redundancy, which leads to the large communication scale of formation, a multi-UAV dynamic target assignment algorithm (CU-CBBA) based on node clustering in communication network is proposed.The algorithm introduces the communication network node grouping clustering strategy. According to the node's degree centrality, feature vector centrality, intermediate centrality and other attributes, the network node importance ranking model is established. A group of key nodes in the network topology structure are selected and the network topology node clustering is completed according to the shortest …

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Research On Modeling And Scheduling Of Virtual Power Plant With Dual Demand Response, Qiang Chen, Yi Wang, Kangshun Li Apr 2023

Research On Modeling And Scheduling Of Virtual Power Plant With Dual Demand Response, Qiang Chen, Yi Wang, Kangshun Li

Journal of System Simulation

Abstract: Virtual power plant technology provides an effective means to aggregate distributed power and user side resources to participate in power scheduling. Most of the existing research focus on the scheduling optimization of distributed energy instead of the demand response of user side. The user side resources are divided into contracted reliable response load and non-contracted random response load, and the load response is regulated through price adjustment mechanism to adapt to the change of distributed. A virtual power plant optimal scheduling model with dual demands response is constructed, in which the maximizing overall profit of the power grid is …

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Voltage And Reactive Power Combinational Evaluation Of Regional Power Grid Based On Ewm-Ahp-Bp Neural Network, Yuqi Ji, Huan Xie, Shaoyu Shi, Ping He, Nan Jin, Huili Wang Apr 2023

Voltage And Reactive Power Combinational Evaluation Of Regional Power Grid Based On Ewm-Ahp-Bp Neural Network, Yuqi Ji, Huan Xie, Shaoyu Shi, Ping He, Nan Jin, Huili Wang

Journal of System Simulation

Abstract: In order to quantitatively evaluate the influence of renewable energy access on voltage and reactive power operation, a combinational evaluation method of voltage and reactive power based on EWM-AHP-BP neural network is proposed to carry out the multi-objective evaluation weight calculation. Considering voltage qualified rate, voltage fluctuation, power factor qualified rate and reactive power reserve, the comprehensive evaluation model is established. The operation data of renewable energy and power load are clustered to divide the typical scenarios and the evaluation model under multiple scenarios is scored by the combination method of entropy weight method and analytic hierarchy process. The …

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Research On Modeling And Solution Method Of Operational Tasks Assignment, Yue Ma, Lin Wu, Shengming Guo Apr 2023

Research On Modeling And Solution Method Of Operational Tasks Assignment, Yue Ma, Lin Wu, Shengming Guo

Journal of System Simulation

Abstract: Aiming at the prewar operational tasks assignment in operation task planning, a multi constraint model of operational tasks assignment is constructed to describe the dynamic mapping relationship between operational tasks and operational units. The solution strategy of decision space pruning and constraint condition judgment is proposed, and the methods of decision variable coding, assignment scheme decoding and phased fitness calculation are described. Differential evolution algorithm is used to work out the solution. The experimental results show that the multi constraint assignment model and solution algorithm can effectively reduce the scale of decision space, and can improve the rationality …

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Validation And Development Of Top-Down Illumination For Optofluidic Biosensors, Matthew Marley Hamblin Apr 2023

Validation And Development Of Top-Down Illumination For Optofluidic Biosensors, Matthew Marley Hamblin

Theses and Dissertations

Lab-on-a-chip devices are changing the way that medical testing is performed by allowing rapid testing with small samples. Optofluidic biosensors are a type of lab-on-a-chip device that use light excitation on a fluid sample. One such application of an optofluidic biosensor is a device that can detect antibiotic resistant bacteria by combining DNA from a sample with fluorescent beads, flowing that sample through a hollow channel, and shining laser light on the channel. If the bacteria tested for is present, the fluorescent beads will give off photons that can be detected as a positive signal. The main method for illumination …

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Knowledge Graph-Based Process Knowledge Reasoning Method For Intelligent Production System, Weikai Yang, Yan Wang, Zhicheng Ji Apr 2023

Knowledge Graph-Based Process Knowledge Reasoning Method For Intelligent Production System, Weikai Yang, Yan Wang, Zhicheng Ji

Journal of System Simulation

Abstract: Aiming at the disadvantages of high redundancy and weakness between knowledge and data in intelligent production system, and the difficulty to perform knowledge reasoning, a process knowledge reasoning method for knowledge maps is proposed. The input information is semantically labeled and classified, the characteristics of the information match are extracted, the extracted local feature and global feature are associated through graph convolution method, and the feature of the difference value information is integrated and mapped with the constructed knowledge graph. Different reasoning rules are used according to different reasoning types, and the association and topology information between instances are …

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A High-Strength Precipitation Hardened Cobalt-Free High-Entropy Alloy, Matthew Luebbe, Jiaqi Duan, Fan Zhang, Jonathan Poplawsky, Hans Pommeranke, Maalavan Arivu, Andrew Hoffman, Mario Buchely, Haiming Wen Apr 2023

A High-Strength Precipitation Hardened Cobalt-Free High-Entropy Alloy, Matthew Luebbe, Jiaqi Duan, Fan Zhang, Jonathan Poplawsky, Hans Pommeranke, Maalavan Arivu, Andrew Hoffman, Mario Buchely, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Recent studies on precipitation-hardened high-entropy alloys (HEAs) demonstrate their high strength and thermal stability, making them promising materials for high-temperature structural applications such as nuclear reactors. However, many existing HEAs contain cobalt (Co), which is unsuitable for nuclear applications because of the long-term activation issue of Co. Co is also expensive and considered a critical material for other applications. Therefore, it is desired to exclude Co from the composition. a Co-free (Fe0.3Ni0.3Mn0.3Cr0.1)88Ti4Al8 HEA was developed and studied in this work. in contrast to previous Co-free HEAs, this alloy is close to Equi atomic in its composition and promises a more …

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On The Performance Enhancement Of Beamspace Mimo And Non-Orthogonal Multiple Access For Future Cellular Networks, Sinasi Cetinkaya Apr 2023

On The Performance Enhancement Of Beamspace Mimo And Non-Orthogonal Multiple Access For Future Cellular Networks, Sinasi Cetinkaya

USF Tampa Graduate Theses and Dissertations

The ever-growing demand for higher data rates and greater data capacity at lower cost has led the mobile cellular industry to investigate new physical layer techniques and possible utilization of unused spectrums at higher frequencies for next-generation cellular networks. Thus, exploitation of the millimeter-wave (mmWave) spectrum and non-orthogonal multiple-access (NOMA) have been envisioned as the most promising enablers in meeting capacity demand. Due to the smaller wavelengths offered in mmWave frequencies, it is possible to deploy many antennas into a relatively smaller physical space in mmWave frequencies. This property leads to a promising integration between mmWave and massive multiple-input multiple-output …

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Dual Resource Constrained Flexible Job Shop Energy-Saving Scheduling Considering Delivery Time, Hongliang Zhang, Jingru Xu, Bo Tan, Gongjie Xu Apr 2023

Dual Resource Constrained Flexible Job Shop Energy-Saving Scheduling Considering Delivery Time, Hongliang Zhang, Jingru Xu, Bo Tan, Gongjie Xu

Journal of System Simulation

Abstract: To handle the flexible job shop energy-saving scheduling with machines and workers constraints, on the considering of delivery time, the optimization model of dual resource constrained flexible job shop energy-saving scheduling is established with the goal of minimizing the total earliness and tardiness penalties, and total energy consumption. An improved non-dominated sorting genetic algorithm II(INSGA-II) is proposed. Aiming at the optimized objectives, a three-stage decoding method is designed to gain more feasible solutions. The dynamic adaptive crossover and mutation operators are applied to get more excellent individuals. The crowding distance is improved to obtain a population with better …

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Research On Improvement Of Social Force Model Based On Non-Motor Vehicle Active Overtaking Behavior, Minghui Yang, Rui Zhang, Qiaobing Yan, Jiahe Wang Apr 2023

Research On Improvement Of Social Force Model Based On Non-Motor Vehicle Active Overtaking Behavior, Minghui Yang, Rui Zhang, Qiaobing Yan, Jiahe Wang

Journal of System Simulation

Abstract: Aiming at the social force model not to illustrate the active overtaking behavior of the rear non-motor vehicle to the front vehicle, an improved social force model is proposed. The traffic behavior characteristics of non-motorized vehicles mixed flow during the active overtaking is analyzed. Considering the compressible characteristics of non-motorized vehicle distancing in different density environments, the model is improved by presenting the concept of dynamic perception space and introducing the overtaking force into the social force model. The model is verified by analyzing the active overtaking behavior, active overtaking distance and speed-density basic graphs. The results indicate that …

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Development Of Models For The Velocity-Pressure Gradient Correlations In Incompressible Wall-Bounded Planar Turbulent Flows Using Multiple Linear Regression, Juampablo E. Heras Rivera Apr 2023

Development Of Models For The Velocity-Pressure Gradient Correlations In Incompressible Wall-Bounded Planar Turbulent Flows Using Multiple Linear Regression, Juampablo E. Heras Rivera

Mechanical Engineering ETDs

In this thesis, the multiple linear regression method is applied to clarify terms and their coefficients in data-driven models for velocity/pressure-gradient (VPG) correlations in the Reynolds stress transport equations. Additionally, a method for developing universal linear models for the VPG correlations with unchanging coefficients when complex conditions arise in a flow is introduced. The generated models were assessed using residual analysis to ensure an appropriate level of accuracy. Data from direct numerical simulation in an incompressible fully-developed turbulent channel flow at Re_tau = 392 with an adverse pressure gradient is used in the study as the data source.

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A High-Strength Precipitation Hardened Cobalt-Free High-Entropy Alloy, Matthew Luebbe, Jiaqi Duan, Fan Zhang, Jonathan Poplawsky, Hans Pommeranke, Maalavan Arivu, Andrew Hoffman, Mario F. Buchely, Haiming Wen Apr 2023

A High-Strength Precipitation Hardened Cobalt-Free High-Entropy Alloy, Matthew Luebbe, Jiaqi Duan, Fan Zhang, Jonathan Poplawsky, Hans Pommeranke, Maalavan Arivu, Andrew Hoffman, Mario F. Buchely, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Recent Studies on Precipitation-Hardened High-Entropy Alloys (HEAs) Demonstrate their High Strength and Thermal Stability, Making Them Promising Materials for High-Temperature Structural Applications Such as Nuclear Reactors. However, Many Existing HEAs Contain Cobalt (Co), Which is Unsuitable for Nuclear Applications Because of the Long-Term Activation Issue of Co. Co is Also Expensive and Considered a Critical Material for Other Applications. Therefore, It is Desired to Exclude Co from the Composition. a Co-Free (Fe0.3Ni0.3Mn0.3Cr0.1)88Ti4Al8 HEA Was Developed and Studied in This Work. in Contrast to Previous Co-Free HEAs, This Alloy is …

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Deficit Irrigation Management For Irrigated Corn In Nebraska: Economically Viable?, Lia Nogueira, Cory Walters, Emily O'Donnell, E. Wesley F. Peterson, Suat Irmak Apr 2023

Deficit Irrigation Management For Irrigated Corn In Nebraska: Economically Viable?, Lia Nogueira, Cory Walters, Emily O'Donnell, E. Wesley F. Peterson, Suat Irmak

Cornhusker Economics

In this study we determine the economic value of deficit irrigation management using both technological and methodological advancements. The use of soil moisture probes represents the technological improvement. We provide improvements in the methodology as follows. Regarding data, we employ a field-size study, instead of plots, where the irrigation decision is determined by the moisture level in the soil measured through a soil moisture probe. Regarding the understanding of the yield response to water, although we examine the commonly used quadratic function, we improve upon this specification by also examining an alternative response function, the linear response stochastic plateau. Our …

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Research On Workshop Logic Modeling And Simulation Based On Finite State Machine, Mingyuan Liu, Jiaxiang Xie, Hao Wu, Jianlin Fu, Guofu Ding Apr 2023

Research On Workshop Logic Modeling And Simulation Based On Finite State Machine, Mingyuan Liu, Jiaxiang Xie, Hao Wu, Jianlin Fu, Guofu Ding

Journal of System Simulation

Abstract: Discrete manufacturing is common in aircraft, ships, electronic equipment, automobile and other manufacturing industries. To ensure the correctness and flexibility of the modeling and simulation process of discrete manufacturing workshops, a logical modeling and simulation method for the production process of discrete manufacturing workshop is proposed. Based on the theory of discrete event dynamic systems and finite-state machines, the attributes and behaviors of the key elements of the discrete manufacturing workshop are abstracted into a unified logic model, and the function of various elements are realized through inheritance. A production process simulation algorithm is designed for the unified model …

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Dynamics Modeling And Online Prediction Of Energy Consumption Of Discrete Manufacturing System, Wei Chen, Yan Wang, Zhicheng Ji Apr 2023

Dynamics Modeling And Online Prediction Of Energy Consumption Of Discrete Manufacturing System, Wei Chen, Yan Wang, Zhicheng Ji

Journal of System Simulation

Abstract: Aiming at the traditional energy consumption modeling methods of discrete manufacturing system being difficult to adapt to the complexity and variability of working conditions, an online dynamic energy consumption modeling method based on real-time data is proposed. The energy consumption affecting factors are determined by analyzing the operation mechanism of the discrete manufacturing system and equipment. An online sequential extreme learning machine algorithm that can dynamically adjust the number of hidden layer nodes is proposed to construct the energy consumption model. The real-time data can update the model quickly. Bernstein's inequality is introduced to improve the model data screening …

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Research Progress Of Opponent Modeling Based On Deep Reinforcement Learning, Haotian Xu, Long Qin, Junjie Zeng, Yue Hu, Qi Zhang Apr 2023

Research Progress Of Opponent Modeling Based On Deep Reinforcement Learning, Haotian Xu, Long Qin, Junjie Zeng, Yue Hu, Qi Zhang

Journal of System Simulation

Abstract: Deep reinforcement learning is an agent modeling method with both deep learning feature extraction ability and reinforcement learning sequence decision-making ability, which can make up for the depleted non-stationary adaptation, complex feature selection and insufficient state-space representation ability of traditional opponent modeling. The deep reinforcement learning-based opponent modeling methods are divided into two categories, explicit modeling and implicit modeling, and the corresponding theories, models, algorithms and applicable scenarios are sorted out according to the categories. The applications of deep reinforcement learning-based opponent modeling techniques on different fields are introduced. The key problems and future development are summarized to provide …

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Adaptive Correction Tracking Algorithm Based On Detector And Locator Fusion, Yecai Guo, Cheng Liu Apr 2023

Adaptive Correction Tracking Algorithm Based On Detector And Locator Fusion, Yecai Guo, Cheng Liu

Journal of System Simulation

Abstract: In order to avoid tracking failure caused by occlusion, rotation and other factors in complex dynamic scenes, an adaptive correction tracking algorithm based on detector and locator fusion is proposed. The locator trains a convolutional neural network (CNN) filter for location estimation by extracting the deep features of target. The CNN filter adds two layers of shallow features to the three layers of the convolution features of original CF2 algorithm, which enhances the extraction of target texture information. The detector calculates the confidence score by extracting histogram of oriented gradient(HOG) feature of target and combining the context information. …

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Cross-Domain Text Sentiment Classification Based On Auxiliary Classification Networks, Na Ma, Tingxin Wen, Xu Jia, Xiaohui Li Apr 2023

Cross-Domain Text Sentiment Classification Based On Auxiliary Classification Networks, Na Ma, Tingxin Wen, Xu Jia, Xiaohui Li

Journal of System Simulation

Abstract: To align exactly the texts with same sentiment polarities of source and target domains, and to enlarge the feature difference of different sentiment texts as much as possible, a domain adaptation model with weighted adversarial networks is proposed. A new structured classification network consisting of a main classification network and an auxiliary classification network is proposed, in which the main classification network is used to perform supervised learning on the labeled texts of the source domain, and the auxiliary classification network is used to improve the distinguishability of the text features. A calculation method of multiple adversarial network weights …

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Trajectory Control Of Crawler Robot Based On Lstm And Smc, Dongyang Liu, Wenwen Zha, Liang Tao, Cheng Zhu, Lichuan Gu, Jun Jiao Apr 2023

Trajectory Control Of Crawler Robot Based On Lstm And Smc, Dongyang Liu, Wenwen Zha, Liang Tao, Cheng Zhu, Lichuan Gu, Jun Jiao

Journal of System Simulation

Abstract: Trajectory tracking is an important part of mobile robot control technology and possesses prospect. Highly nonlinear dynamic characteristics are the main obstacles of controller design. A SMC method based on LSTM and quasi-sliding mode is proposed. The kinematics model and dynamics model of the tracked vehicle are given, and the sliding mode control system is established based on the dynamics model. LSTM network based on deep learning method is designed to control and compensate the unknown interference items, reduce the influence of external interference, and reduce the tremor phenomenon by combining the advantages of LSTM network and quasi-sliding …

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Multi-Agent Cooperative Combat Simulation In Naval Battlefield With Reinforcement Learning, Ding Shi, Xuefeng Yan, Lina Gong, Jingxuan Zhang, Donghai Guan, Mingqiang Wei Apr 2023

Multi-Agent Cooperative Combat Simulation In Naval Battlefield With Reinforcement Learning, Ding Shi, Xuefeng Yan, Lina Gong, Jingxuan Zhang, Donghai Guan, Mingqiang Wei

Journal of System Simulation

Abstract: Due to the rapidly-changed situations of future naval battlefields, it is urgent to realize the high-quality combat simulation in naval battlefields based on artificial intelligence to comprehensively optimize and improve the combat effectiveness of our army and defeat the enemy. The collaboration of combat units is the key point and how to realize the balanced decision-making among multiple agents is the first task. Based on decoupling priority experience replay mechanism and attention mechanism, a multi-agent reinforcement learning-based cooperative combat simulation (MARL-CCSA) network is proposed. Based on the expert experience, a multi-scale reward function is designed, on which a naval …

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I-Nicemo Enhanced Algorithm Based On Intersection Angel Geometry, Yifan He, Yulin He, Yongda Cai, Zhexue Huang Apr 2023

I-Nicemo Enhanced Algorithm Based On Intersection Angel Geometry, Yifan He, Yulin He, Yongda Cai, Zhexue Huang

Journal of System Simulation

Abstract: To exactly determine the number of cluster centers and correctly identify the candidate cluster centers, an I-niceMO enhanced(I-niceMOEn) algorithm based on intersection angel geometry is proposed. As many distributions of intersection angles and distances as possible between observation points and data points are utilized to recognize the candidate cluster centers to avoid the neglection of cluster centers. The spectral clustering algorithm is used to automatically merge the candidate cluster centers according to the eigenvalues of Laplacian matrices. The number of final cluster centers is determined by the number of merged candidate cluster centers. The number of clusters can be …

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Bottleneck Drift Fluctuation Analysis Of Discrete Remanufacturing System Under Disturbance, Yongzhang Zhou, Yan Wang, Zhicheng Ji Apr 2023

Bottleneck Drift Fluctuation Analysis Of Discrete Remanufacturing System Under Disturbance, Yongzhang Zhou, Yan Wang, Zhicheng Ji

Journal of System Simulation

Abstract: Considering comprehensively the influence of each production process on the bottleneck degree of discrete remanufacturing system, the interval bottleneck index matrix is established by collecting data repeatedly in the observation stage to obtain the comprehensive bottleneck index of equipment, which is used as the identification basis. Aiming at the volatility of bottleneck drift in the uncertain environment of discrete remanufacturing system, based on the interval bottleneck index matrix and comprehensive bottleneck index, a theoretical method of visual dynamic analysis including system sensitivity coefficient, machine sensitivity coefficient and bottleneck drift judgment model is established. The discrete event simulation case is …

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Shared Subnet Synthesis And Application Of Object-Oriented Pres Net, Chuanliang Xia, Maibo Guo, Zhuangzhuang Wang, Yan Sun Apr 2023

Shared Subnet Synthesis And Application Of Object-Oriented Pres Net, Chuanliang Xia, Maibo Guo, Zhuangzhuang Wang, Yan Sun

Journal of System Simulation

Abstract: Focus on embedded system modeling, a solution to obtain a synthesized net via the shared subnet of an extended Petri net is proposed. Object-oriented technology and Petri net-based representation for embedded system (PRES net) are merged to obtain an object-oriented PRES net (OOPRES net). A method of synthesized operation of the shared subnet of OOPRES net is proposed, and the preservation of the liveness and boundedness of synthesized net system is studied. Taking the modeling analysis of intelligent transportation system as an example, the effectiveness of the synthesized method is verified. The method can provide an effective way for …

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Construction Technology Of Hand Posture Dataset Based On Virtual Simulation Method, Jiaxin Chen, Guohui Zhou, Jianbai Yang Apr 2023

Construction Technology Of Hand Posture Dataset Based On Virtual Simulation Method, Jiaxin Chen, Guohui Zhou, Jianbai Yang

Journal of System Simulation

Abstract: Hand posture is an important carrier of human-computer interaction, and the acquisition and recognition of posture information largely depends on the hand posture dataset. Existing datasets can be divided into two categories, real datasets and synthetic datasets. As real data is limited by equipment, environment, and other factors, the classification of hand posture is insufficient and the annotation is mixed with a lot of manual errors. The existing synthetic data can solve the data scale problem of real data, but the synthetic hand posture volume is limited and with some unreasonable kinematic postures of which the data form are …

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Research On Unmanned Swarm Combat System Adaptive Evolution Model Simulation, Zhiqiang Li, Yuanlong Li, Laixiang Yin, Xiangping Ma Apr 2023

Research On Unmanned Swarm Combat System Adaptive Evolution Model Simulation, Zhiqiang Li, Yuanlong Li, Laixiang Yin, Xiangping Ma

Journal of System Simulation

Abstract: Aiming at the fact that the intelligent unmanned swarm combat system is mainly composed of large-scale combat individuals with limited behavioral capabilities and has limited ability to adapt to the changes of battlefield environment and combat opponents, a learning evolution method combining genetic algorithm and reinforcement learning is proposed to construct an individual-based unmanned bee colony combat system evolution model. To improve the adaptive evolution efficiency of bee colony combat system, an improved genetic algorithm is proposed to improve the learning and evolution speed of bee colony individuals by using individual-specific mutation optimization strategy. Simulation experiment on …

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Atmospheric Corrosion Simulation Of Air Conditioning Heat Exchanger In Service Under Marine Environment, Huang Peng, Jun Wang, Li Qi, Zhidong Wu Apr 2023

Atmospheric Corrosion Simulation Of Air Conditioning Heat Exchanger In Service Under Marine Environment, Huang Peng, Jun Wang, Li Qi, Zhidong Wu

Journal of System Simulation

Abstract: Aiming at the performance degradation of airconditioner heat exchanger caused by serious corrosion under marine environment, an atmospheric corrosion simulation method is studied to analyze and predict the influence on corrosion conditions of marine environment and working condition of air conditioner heat exchanger. From the acquisition of material parameters, the construction the model and the setting of boundary conditions, the atmospheric corrosion simulation process of air conditioner heat exchanger in service under marine environment is systematically introduced, and a method to verify the accuracy of the simulation model by using an artificially accelerated environmental test chamber is provided. From …

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Quantifying And Managing Anthropogenic And Drought Influences On Instream Temperatures, Abbygael Johnson Apr 2023

Quantifying And Managing Anthropogenic And Drought Influences On Instream Temperatures, Abbygael Johnson

Student Research Symposium

The western US is currently experiencing effects of one of the worst droughts in 1200 years. These effects are evident in our rivers, as shown by broad scale reductions in baseflow. This lack of runoff combined with growing demands has resulted in the overallocation of the water contained within our rivers and reservoirs. Water temperature is the key factor in many biological, chemical, and physical processes, making it critical to the health of ecosystems . River temperatures are a function of many factors including weather and tree canopy, but also instream flow volumes and water residence time. When instream flows …

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Understanding The Role Of A Putative Type I Polyketide Synthase In Chlorflavonin Biosynthesis, Ammar Mussaji Apr 2023

Understanding The Role Of A Putative Type I Polyketide Synthase In Chlorflavonin Biosynthesis, Ammar Mussaji

Student Research Symposium

Flavonoids are an important class of plant secondary metabolites with a variety of biological functions in the development processes of hosts. These molecules have also shown health-benefiting properties such as antioxidant and anti-inflammatory activities. As such, they are commonly used as pharmaceuticals and nutraceuticals. In plants, flavonoids are assembled through a type III polyketide synthase (PKS) and associated tailoring enzymes such as hydroxylase and glycosyltransferase. Some filamentous fungi also produce flavonoids, such as chlorflavonin from Aspergillus candidus. Chlorflavonin is a novel halogenated flavonoid found in nature reported to possess antifungal and anti-tuberculosis activity. Unlike plants, the biosynthetic process of flavonoids …

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Glycosylation Of Anti-Tb Agent Chlorflavonin For Combating Mycobacterium Tuberculosis, Jie Ren Apr 2023

Glycosylation Of Anti-Tb Agent Chlorflavonin For Combating Mycobacterium Tuberculosis, Jie Ren

Student Research Symposium

More than two billion people were infected by the bacterial pathogen Mycobacterium tuberculosis (Mtb) in 2020. However, during the past 50 years, the first-line (isoniazid, delamanid, and rifampicin) and second-line (capreomycin, streptomycin, and cycloserine) therapies have remained unchanged with disadvantages such as long treatment periods and severe side effects. The slow development of anti-TB drugs cannot combat the fast development of drug resistant M. tuberculosis strains from multidrug-resistant (MDR) into extensively drug resistant (XDR), which further hinders the World Health Organization’s goal to end the global TB pandemic by the year 2035. Flavonoids are a type of natural product with …

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