期刊文献+
共找到14篇文章
< 1 >
每页显示 20 50 100
Research on Restoration of Murals Based on Diffusion Model and Transformer
1
作者 Yaoyao Wang Mansheng Xiao +2 位作者 Yuqing Hu Jin Yan Zeyu Zhu 《Computers, Materials & Continua》 SCIE EI 2024年第9期4433-4449,共17页
Due to the limitations of a priori knowledge and convolution operation,the existing image restoration techniques cannot be directly applied to the cultural relics mural restoration,in order to more accurately restore ... Due to the limitations of a priori knowledge and convolution operation,the existing image restoration techniques cannot be directly applied to the cultural relics mural restoration,in order to more accurately restore the original appearance of the cultural relics mural images,an image restoration based on the denoising diffusion probability model(Denoising Diffusion Probability Model(DDPM))and the Transformer method.The process involves two steps:in the first step,the damaged mural image is firstly utilized as the condition to generate the noise image,using the time,condition and noise image patch as the inputs to the noise prediction network,capturing the global dependencies in the input sequence through the multi-attentionmechanismof the input sequence and feedforward neural network processing,and designing a long skip connection between the shallow and deep layers in the Transformer blocks between the shallow and deep layers using long skip connections to fuse the feature information of global and local outputs to maintain the overall consistency of the restoration results;In the second step,taking the noisy image as a condition to direct the diffusion model to back sample to generate the restored image.Experiment results show that the PSNR and SSIM of the proposedmethod are improved by 2%to 9%and 1%to 3.3%,respectively,which are compared to the comparison methods.This study proposed synthesizes the advantages of the diffusionmodel and deep learningmodel to make themural restoration results more accurate. 展开更多
关键词 TRANSFORMER deep learning noise estimation network diffusion model mural restoration
下载PDF
State estimation over a communication network:measurement or estimate communication?
2
作者 Ling SHI Ye YUAN Michael Z. Q. CHEN 《控制理论与应用(英文版)》 EI 2010年第1期20-26,共7页
In this paper we consider the problem of state estimation over a communication network. Using estimation quality as a metric, two communication schemes are studied and compared. In scheme one, each sensor node communi... In this paper we consider the problem of state estimation over a communication network. Using estimation quality as a metric, two communication schemes are studied and compared. In scheme one, each sensor node communicates its measurement data to the remote estimator, while in scheme two, each sensor node communicates its local state estimate to the remote estimator. We show that with perfect communication link, if the sensor has unlimited computation capability, the two schemes produce the same estimate at the estimator, and if the sensor has limited computation capability, scheme one is always better than scheme two. On the other hand, when data packet drops occur over the communication link, we show that if the sensor has unlimited computation capability, scheme two always outperforms scheme one, and if the sensor has limited computation capability, we show that in general there exists a critical packet arrival rate, above which scheme one outperforms scheme two. Simulations are provided to demonstrate the two schemes under various circumstances. 展开更多
关键词 networked estimation Kalman filtering Packet-dropping network
下载PDF
Novel active fault-tolerant control scheme and its application to a double inverted pendulum system 被引量:3
3
作者 Cui Ping Weng Zhengxin Patton Ron 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第1期134-140,共7页
On the basis of the gain-scheduled H∞ design strategy, a novel active fault-tolerant control scheme is proposed. Under the assumption that the effects of faults on the state-space matrices of systems can be of affine... On the basis of the gain-scheduled H∞ design strategy, a novel active fault-tolerant control scheme is proposed. Under the assumption that the effects of faults on the state-space matrices of systems can be of affine parameter dependence, a reconfigurable robust H∞ linear parameter varying controller is developed. The designed controller is a function of the fault effect factors that can be derived online by using a well-trained neural network. To demonstrate the effectiveness of the proposed method, a double inverted pendulum system, with a fault in the motor tachometer loop, is considered. 展开更多
关键词 active fault-tolerant control neural network estimator gain-scheduled controller double inverted pendulum.
下载PDF
Resource Allocation for Physical Layer Security in Heterogeneous Network with Hidden Eavesdropper 被引量:5
4
作者 GONG Shiqi XING Chengwen +1 位作者 FEI Zesong KUANG Jingming 《China Communications》 SCIE CSCD 2016年第3期82-95,共14页
The tremendous performance gain of heterogeneous networks(Het Nets) is at the cost of complicated resource allocation. Considering information security, the resource allocation for Het Nets becomes much more challengi... The tremendous performance gain of heterogeneous networks(Het Nets) is at the cost of complicated resource allocation. Considering information security, the resource allocation for Het Nets becomes much more challenging and this is the focus of this paper. In this paper, the eavesdropper is hidden from the macro base stations. To relax the unpractical assumption on the channel state information on eavesdropper, a localization based algorithm is first given. Then a joint resource allocation algorithm is proposed in our work, which simultaneously considers physical layer security, cross-tier interference and joint optimization of power and subcarriers under fairness requirements. It is revealed in our work that the considered optimization problem can be efficiently solved relying on convex optimization theory and the Lagrangian dual decomposition method is exploited to solve the considered problem effectively. Moreover, in each iteration the closed-form optimal resource allocation solutions can be obtained based on the Karush-Kuhn-Tucker(KKT) conditions. Finally, the simulation results are given to show the performance advantages of the proposed algorithm. 展开更多
关键词 resource allocation physical layer security heterogeneous networks RSS-based location estimation lagrangian dual decomposition
下载PDF
An Improved Underwater Acoustic Network Localization Algorithm 被引量:5
5
作者 WU Zhehao LI Xia 《China Communications》 SCIE CSCD 2015年第3期77-83,共7页
Underwater sensor network can achieve the unmanned environmental monitoring and military monitoring missions.Underwater acoustic sensor node cannot rely on the GPS to position itself,and the traditional indirect posit... Underwater sensor network can achieve the unmanned environmental monitoring and military monitoring missions.Underwater acoustic sensor node cannot rely on the GPS to position itself,and the traditional indirect positioning methods used in Ad Hoc networks are not fully applicable to the localization of underwater acoustic sensor networks.In this paper,we introduce an improved underwater acoustic network localization algorithm.The algorithm processes the raw data before localization calculation to enhance the tolerance of random noise.We reduce the redundancy of the calculation results by using a more accurate basic algorithm and an adjusted calculation strategy.The improved algorithm is more suitable for the underwater acoustic sensor network positioning. 展开更多
关键词 acoustic sensor network localization algorithm greedy algorithm interval estimation
下载PDF
Intelligent Resources Management System Design in Information Centric Networking 被引量:2
6
作者 Hengyang Zhang Shixiang Zhu +2 位作者 Renchao Xie Tao Huang Yunjie Liu 《China Communications》 SCIE CSCD 2017年第8期105-123,共19页
Information centric networking(ICN) is a new network architecture that is centred on accessing content. It aims to solve some of the problems associated with IP networks, increasing content distribution capability and... Information centric networking(ICN) is a new network architecture that is centred on accessing content. It aims to solve some of the problems associated with IP networks, increasing content distribution capability and improving users' experience. To analyse the requests' patterns and fully utilize the universal cached contents, a novel intelligent resources management system is proposed, which enables effi cient cache resource allocation in real time, based on changing user demand patterns. The system is composed of two parts. The fi rst part is a fi ne-grain traffi c estimation algorithm called Temporal Poisson traffi c prediction(TP2) that aims at analysing the traffi c pattern(or aggregated user requests' demands) for different contents. The second part is a collaborative cache placement algorithm that is based on traffic estimated by TP2. The experimental results show that TP2 has better performance than other comparable traffi c prediction algorithms and the proposed intelligent system can increase the utilization of cache resources and improve the network capacity. 展开更多
关键词 information centric networking traffi c estimation cache resources allocation time series analysis intelligent analysis
下载PDF
TYRE DYNAMICS MODELLING OF VEHICLE BASED ON SUPPORT VECTOR MACHINES 被引量:2
7
作者 ZHENG Shuibo TANG Houjun +1 位作者 HAN Zhengzhi ZHANG Yong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2006年第4期558-565,共8页
Various methods of tyre modelling are implemented from pure theoretical to empirical or semi-empirical models based on experimental results. A new way of representing tyre data obtained from measurements is presented ... Various methods of tyre modelling are implemented from pure theoretical to empirical or semi-empirical models based on experimental results. A new way of representing tyre data obtained from measurements is presented via support vector machines (SVMs). The feasibility of applying SVMs to steady-state tyre modelling is investigated by comparison with three-layer backpropagation (BP) neural network at pure slip and combined slip. The results indicate SVMs outperform the BP neural network in modelling the tyre characteristics with better generalization performance. The SVMsqyre is implemented in 8-DOF vehicle model for vehicle dynamics simulation by means of the PAC 2002 Magic Formula as reference. The SVMs-tyre can be a competitive and accurate method to model a tyre for vehicle dynamics simuLation. 展开更多
关键词 Support vector machines(SVMs) Backpropagation(BP) neural network Tyre model Regression estimation Magic formula
下载PDF
Recommending Personalized POIs from Location Based Social Network
8
作者 Haiying Che Di Sang Billy Zimba 《Journal of Beijing Institute of Technology》 EI CAS 2018年第1期137-145,共9页
Location based social networks( LBSNs) provide location specific data generated from smart phone into online social networks thus people can share their points of interest( POIs). POI collections are complex and c... Location based social networks( LBSNs) provide location specific data generated from smart phone into online social networks thus people can share their points of interest( POIs). POI collections are complex and can be influenced by various factors,such as user preferences,social relationships and geographical influence. Therefore,recommending new locations in LBSNs requires to take all these factors into consideration. However,one problem is how to determine optimal weights of influencing factors in an algorithm in which these factors are combined. The user similarity can be obtained from the user check-in data,or from the user friend information,or based on the different geographical influences on each user's check-in activities. In this paper,we propose an algorithm that calculates the user similarity based on check-in records and social relationships,using a proposed weighting function to adjust the weights of these two kinds of similarities based on the geographical distance between users. In addition,a non-parametric density estimation method is applied to predict the unique geographical influence on each user by getting the density probability plot of the distance between every pair of user's check-in locations. Experimental results,using foursquare datasets,have shown that comparisons between the proposed algorithm and the other five baseline recommendation algorithms in LBSNs demonstrate that our proposed algorithm is superior in accuracy and recall,furthermore solving the sparsity problem. 展开更多
关键词 location based social network personalized geographical influence location recommendation non-parametric probability estimates
下载PDF
Probability-based Clustering and Its Application to WLAN Location Estimation 被引量:3
9
作者 张明华 张申生 曹健 《Journal of Shanghai Jiaotong university(Science)》 EI 2008年第5期547-552,共6页
Wireless local area networks (WLAN) localization based on received signal strength is becoming an important enabler of location based services. Limited efficiency and accuracy are disadvantages to the deterministic lo... Wireless local area networks (WLAN) localization based on received signal strength is becoming an important enabler of location based services. Limited efficiency and accuracy are disadvantages to the deterministic location estimation techniques. The probabilistic techniques show their good accuracy but cost more computation overhead. A Gaussian mixture model based on clustering technique was presented to improve location determination efficiency. The proposed clustering algorithm reduces the number of candidate locations from the whole area to a cluster. Within a cluster, an improved nearest neighbor algorithm was used to estimate user location using signal strength from more access points. Experiments show that the location estimation time is greatly decreased while high accuracy can still be achieved. 展开更多
关键词 probability-based clustering Gaussian mixture model wireless local area networks (WLAN) location estimation received signal strength
原文传递
Event-based Control and Filtering of Networked Systems:A Survey 被引量:7
10
作者 Lei Zou Zi-Dong Wang Dong-Hua Zhou 《International Journal of Automation and computing》 EI CSCD 2017年第3期239-253,共15页
In recent years, theoretical and practical research on event-based communication strategies has gained considerable research attention due primarily to their irreplaceable superiority in resource-constrained systems(... In recent years, theoretical and practical research on event-based communication strategies has gained considerable research attention due primarily to their irreplaceable superiority in resource-constrained systems(especially networked systems). For networked systems, event-based transmission scheme is capable of improving the efficiency in resource utilization and prolonging the lifetime of the network components compared with the widely adopted periodic transmission scheme. As such, it would be interesting to 1) examining how the event-triggering mechanisms affect the control or filtering performance for networked systems, and 2) developing some suitable approaches for the controller and filter design problems. In this paper, a bibliographical review is presented on event-based control and filtering problems for various networked systems. First, the event-driven communication scheme is introduced in detail according to its engineering background, characteristic, and representative research frameworks. Then, different event-based control and filtering(or state estimation) problems are categorized and then discussed. Finally, we conclude the paper by outlining future research challenges for event-based networked systems. 展开更多
关键词 Event-triggered transmission networked systems event-based control event-based filtering event-triggered distributed state estimation distributed control with event-based protocol
原文传递
MIMO Channel Estimation and Equalization Using Three-Layer Neural Networks with Feedback
11
作者 张玲 张贤达 《Tsinghua Science and Technology》 SCIE EI CAS 2007年第6期658-662,共5页
This paper describes a channel estimation and equalization algorithm using three-layer artificial neural networks (ANNs) with feedback for multiple input multiple output wireless communication systems. An ANN struct... This paper describes a channel estimation and equalization algorithm using three-layer artificial neural networks (ANNs) with feedback for multiple input multiple output wireless communication systems. An ANN structure with feedback was designed to use different learning algorithms in the different ANN layers. This actually forms a Turbo iteration process between the different algorithms which effectively improves the estimation performance of the channel equalizer. Simulation results show that this channel equalization algorithm has better computational efficiency and faster convergence than higher order statistics based algorithms. 展开更多
关键词 multiple input multiple output channel equalization channel estimation artificial neural networks symbol estimation
原文传递
Time delay recursive neural network-based direct adaptive control for a piezo-actuated stage 被引量:1
12
作者 WANG YiFan ZHOU MiaoLei +2 位作者 SHEN ChuanLiang CAO WenJing HUANG XiaoLiang 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2023年第5期1397-1407,共11页
Piezo-actuated stage is a core component in micro-nano manufacturing field.However,the inherent nonlinearity,such as rate-dependent hysteresis,in the piezo-actuated stage severely impacts its tracking accuracy.This st... Piezo-actuated stage is a core component in micro-nano manufacturing field.However,the inherent nonlinearity,such as rate-dependent hysteresis,in the piezo-actuated stage severely impacts its tracking accuracy.This study proposes a direct adaptive control(DAC)method to realize high precision tracking.The proposed controller is designed by a time delay recursive neural network.Compared with those existing DAC methods designed under the general Lipschitz condition,the proposed control method can be easily generalized to the actual systems,which have hysteresis behavior.Then,a hopfield neural network(HNN)estimator is proposed to adjust the parameters of the proposed controller online.Meanwhile,a modular model consisting of linear submodel,hysteresis submodel,and lumped uncertainties is established based on the HNN estimator to describe the piezoactuated stage in this study.Thus,the performance of the HNN estimator can be exhibited visually through the modeling results.The proposed control method eradicates the adverse effects on the control performance arising from the inaccuracy in establishing the offline model and improves the capability to suppress the influence of hysteresis on the tracking accuracy of piezo-actuated stage in comparison with the conventional DAC methods.The stability of the control system is studied.Finally,a series of comparison experiments with a dual neural networks-based data driven adaptive controller are carried out to demonstrate the superiority of the proposed controller. 展开更多
关键词 piezo-actuated stage direct adaptive control time delay recursive neural network hopfield neural network estimator
原文传递
Incident Detection Method of Expressway Based on Traffic Flow Simulation Model 被引量:1
13
作者 Shu-Bin Li Tao Sun +1 位作者 Dan-Ni Cao Lin Zhang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2019年第4期468-474,共7页
The expressway traffc incidents have the characteristics of high harmful, strong destructive and refractory.Incident detection can guarantee smooth operation of the expressway, reduce traffc congestion and avoid secon... The expressway traffc incidents have the characteristics of high harmful, strong destructive and refractory.Incident detection can guarantee smooth operation of the expressway, reduce traffc congestion and avoid secondary accident by informing the accident, detection and treatment timely. In this paper, an incident detection method is proposed using the toll station data that takes into account the traffc ratio at the entrances and crossway in the network. The expressway traffc simulation model is improved and a simulation algorithm is established to describe the movement of the vehicles. A numerical example is experimented on the expressway network of Shandong province. The proposed method can effectively detect the expressway incidents, and dynamically estimate the traffc network states so as to provide advice for the highway management department. 展开更多
关键词 EXPRESSWAY traffc flow simulation model incident detection network state estimation
原文传递
A Systematic Design of Emulators for Multivariable Non Square and Nonlinear Systems
14
作者 Nesrine Bahri Asma Atig +2 位作者 Ridha Ben Abdennour Fabrice Druaux Dimitri Lefebvre 《International Journal of Automation and computing》 EI CSCD 2017年第6期742-754,共13页
In this paper, multimodel and neural emulators are proposed for uncoupled multivariable nonlinear plants with unknown dynamics. The contributions of this paper are to extend the emulators to multivariable non square s... In this paper, multimodel and neural emulators are proposed for uncoupled multivariable nonlinear plants with unknown dynamics. The contributions of this paper are to extend the emulators to multivariable non square systems and to propose a systematic method to compute the multimodel synthesis parameters. The effectiveness of the proposed emulators is shown through two simulation examples. The obtained results are very satisfactory, they illustrate the performance of both emulators and show the advantages of the multimodel emulator relatively to the neural one. 展开更多
关键词 Uncoupled multimodel neural networks emulation multivariable nonlinear systems parameters estimation
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部