共查询到20条相似文献，搜索用时 15 毫秒
1.
Wireless sensor networks (WSN) is a novel technology about acquiring and processing information. The designer of WSN must have a thorough understand about architecture, protocol and characteristics of WSN. This paper describes communication architecture, component of node and available building scheme for WSN in detail, analyzes the characteristics of all topologies, and presents a protocol stack based on layer theory. The popular wireless communication models are discussed, characteristics and features are also analyzed, which provide a guidance for designer. 相似文献
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A dynamic control model for the secondary cooling of slab casting is presented to reduce the difference between the actual temperature and the goal surface temperature of slab. The model, which is based on the BP neural networks for forecasting the temperature and the fuzzy neural networks for dynamically controlling the water in the secondary cooling in the continuous casting, could timely adjust and allocate the water according to the speed and temperature of slab. A series of tests have been conducted based on inputs of the No. 2 slab caster in a steel plant. It has been shown that the model, which integrate the charateristics of water controlling problem in secondary cooling into the temperature status of slab during the cooling process, can control the water in secondary cooling efficiently and dynamically according to the situation of actual production. 相似文献
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In this paper, a predictive control approach using neural networks for active power filter is proposed. The control system of active power filter using this method make using of the internal model control technology based on neural networks, meanwhile, to solve its questions such as lag because of calculating using neural networks, a predictive model based on neural networks is introduced. Simulation analysis shows that this control approach can compensate the lag of system and take advantage of self-adaptive characteristic of neural networks. Good result can be obtained. 相似文献
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Aiming at systems which are of characteristics of multi-input and multi-output, nonlinearity and time-variation in the industrial control fields, this paper presents a intelligent PID control method based on ameliorative RBF neural networks, which constructs RBF neural networks identifier on-line and identifies a controlled object on-line by means of adopting the nearest neighbor-clustering algorithm, and adjusts parameters of PID controller on-line and realizes decoupiing control of multivariable, nonlinear and time-variation system. The simulation result indicates that the controller can get parameters which are optimal under some control law, it makes the decoupled system, compared to the PID control method based on the conventional RBF neural networks, has perfect dynamic and static performances, possesses the advantages of high precision, quick response speed and is of great adaptability and robustness. 相似文献
5.
Liang Shan Shi Weiren Mao Xindong 《保鲜与加工》1998,(2):34-39
Combining artificial neural networks(ANN) with fuzzy system theory,a kind of modelling & control method of fuzzy system based on ANN is presented.The simulation researches have verified that the proposed approach can be applied effectively to a number of control systems which are defficult to build strict mathematical model. 相似文献
6.
Based on the neural networks, object oriented technique, artificial intelligence technique and computer networks, an intelligent fault diagnosis system of the power plant whose need of the operation is presented. The architecture of software system , hardware system and corresponding databases is designed. The software of collecting data is established. The intelligent fault diagnosis system based on neural networks and object oriented technique is also developed. The physical system operation has been shown that the method mentioned above is feasible and effective in practice. 相似文献
7.
The discussion on innovation networks of patents or papers has attracted many economic geographers; however, the Industrial Technology Innovation Strategy Alliance (ITISA) has been ignored, although it is also an important innovation form of firms, and the formation mechanism of alliance innovation networks is unclear. This study is based on the data of Shanghai high‐tech ITISAs between 2010 and 2015, and employs the methods of social networks and negative binomial regression to analyse the actor structure, spatial structure, and proximity mechanism of innovation networks of Shanghai high‐tech ITISAs. Results highlight the following: (a) Firms comprise the largest number of actors in alliance innovation networks, and universities, research institutions, and industry associations also play some roles. (b) The local and rooted characteristics of the innovation networks of ITISAs are obvious. The spatial distribution of innovation partners is mainly in Shanghai, and a few innovation actors are located in neighbouring cities, such as Suzhou, Hangzhou, and Ningbo in the Yangtze River Delta Urban Agglomeration. (c) Proximity significantly promotes the formation of innovation networks in an ITISA and contributes to the improvement of innovation ability, and organizational proximity plays a greater role than geographical proximity or cognitive proximity. 相似文献
8.
Dong Jingrong Yang Xiutai 《保鲜与加工》1998,(4):34-38
A new method for evaluation of transversal economic benefits is researched by fuzzy neural networks, BP algorithm is used to learn the connection weights of the fuzzy neural networks and partitions of fuzzy subsets. It has been shown by the modeling and evaluating results about the economic benefit index system of ten enterprises that the method has reinforcement learning properties and universalized capabilities. with respect to modeling and evaluating of nonlinear systems which have some uncertainties, the method is available. 相似文献
9.
基于无线传感器网络的鱼塘监控系统 总被引：3，自引：1，他引：2
本文设计了基于无线传感器网络的鱼塘实时在线智能监控系统,有效解决了传统的鱼塘观测手段存在的问题,例如：费时费力、步骤复杂、成本高等。该系统在鱼塘的监测区域中利用无线传感器节点,测得该区域中的温度和溶氧量,并通过Zigbee网络将数据传输到终端控制系统,控制系统作出判断并发出报警信号和控制增氧机的状态。系统中以MSP430和XBEE模块为核心芯片,能够实时在线监测鱼塘中的一些参数,例如温度、溶氧量等。同时该系统还可以进一步扩展使用GPRS或3G网络实现远程监控。 相似文献
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This paper has presented a multi-objective fuzzy optimal power flow medel.Inthe model , the multiple objectives, such as the minimum generation cost and the minimum powerloss, have been considered simultaneously, A new algorithm based on neural network models is aisopresented,in which the neural networks are employed to express, the membership function of fuzzysets and solve the optimization problems. The validity of model and algorithm is verified with numerical examples. 相似文献
12.
为提高农业专家系统的工作效率和使用效果,促进其普及应用,对无线通信网络应用于农业专家系统进行探讨,设计基于3G网络的可视化病虫害系统,用户可通过手机终端访问系统,传送病虫害特征信息,在线获取病虫害防治解决方案。结果表明该系统具有良好的普适性,为果树栽培管理提供了技术支撑工具。 相似文献
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A method based on radial basis function networks for forecasting chaotic time series is proposed.The nonlinear time series identification problem is formulated with a nonlinear autoregressive moving average(NARMAX)model then a new identification algorithm based on dynamic radial basis function networks is proposed.Then this method is applied to the estimation of embedding dimension for chaotic time series of Henon mapping and the confirmation of the chaotic phenomena in stock markets of China,from which one can get the desired results.Further research directions are also pointed out. 相似文献
15.
From the viewpoint of nonlinear dynamics, this review outlines the recent advances as well as some open problems in the study of neural networks with time delays, an important class of delayed systems in various neural network models. The survey includes three aspects as fellows: the dynamic features, available approaches and advances in research on most attractive problems. The evolution of a delayed neural network depends not only on the current state of the systems but also on previous ones. Hence, a delayed neural network should be modeled by a functional differential equation, the solution space of which is of infinite dimensions. Therefore, the dynamical behavior of delayed neural networks is very complex. 相似文献
16.
For the high density of distributed heterogeneity nodes in wireless sensor networks (WSNs), the optimal sensor deployment is studied. A cost optimal heterogeneous sensor deployment scheme based on genetic algorithm is proposed. The cost of sensor node deployment is used as objective function for optimization computation subjected to network coverage and fault tolerance to obtain the suitable types and positions of the sensors. The algorithm can be used for boolean sensing model as well as probabilistic sensing model. The simulation results demonstrate that the proposed algorithm converges fast toward the optimal solutions and reduces the cost of sensor deployment, which is feasible for heterogenous nodes deployment in WSNs. 相似文献
17.
To overcome the limitations of the standard ellipsoidal unit neural networks, some new approaches used in ellipsoidal unit neural networks have been proposed. These new approaches address three main issues: firstly, to understand better and represent the nature of fault classification boundaries; secondly, to determine the network structure without the usual trial and error schemes; lastly, to avoid erroneous generalizations. The application in CSTR shows that the ellipsoidal unit networks can possess arbitrary nonlinear classifying ability, nonlinear interfacial describing ability, and obtain accurate and efficient diagnosis results. 相似文献
18.
In Vietnam's capital city Hanoi, the growing popularity of application based (app-based) motorbike taxis has offered many inhabitants new opportunities to pursue a mobile livelihood with ride-hailing platforms. Nonetheless, as this influx of app-based drivers has hit the city's streets, specific livelihood and mobility frictions have emerged, notably with informal, ‘traditional’ motorbike taxi drivers, or xe ôm. In this paper we analyse these evolving sites and moments of friction and their impacts on driver livelihoods and mobilities for both driver groups. We draw conceptually on debates regarding mobility, platform economies, and urban livelihoods, while specifically interrogating the concept of friction to highlight three possible analytical applications. Methodologically, we interpret static and ride-along interviews completed with over 130 drivers. We highlight a range of tactics ‘traditional’ and app-based motorbike taxi drivers have employed to respond to rising frictions, defend their ‘turf’, and maintain their street-based livelihoods. Driver responses reveal differing access to distinctive forms of social capital and social networks, and contrasting levels of agency regarding their mobilities. By conceptually teasing apart the notion of friction, we wish to expand and deepen understandings of the experiences of vulnerability, precarity, and other impacts of platformisation for different motorbike taxi driver cohorts. 相似文献
19.
The equivalence between fuzzy neural networks model for max-min fuzzy operator and S.Stoeva's is proved by studying the fuzzy neural networks model for max-min fuzzy based on S.Stoeva's.Then the paper proposes the fuzzy backpropagation learning algorithms for changing fuzzy power and probes their convergence properties.Finally,it simulates experiment such as state monitoring of turbo-generator set.The results show that the fuzzy backpropagation learning algorithms presented are convergent on condition that the output of training sample is between maximum and minimum of its input. 相似文献
20.
To solve the instability problem of established sample in the neural network evaluation method for mine ventilation system, a comprehensive evaluation of the ventilation system is carried out based on rough sets and BP neural networks. Taking the ventilation system of a mine as an example, the classification quality of raw data samples are tested by using rough set data analysis system. Then, based on artificial neural network theory, a rough sets-neural network evaluation model of a mine ventilation system is established and a new rough sets-neural network evaluation method of mine ventilation system is formed. The results show that, after the model validation of data and application, its theoretical evaluation results are in line with the actual situation, and the network total error is less than 0.004. It shows that the comprehensive evaluation method based on rough sets-neural networks has a good effect in evaluating mine ventilation system in practical application. 相似文献