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131.
针对片状颗粒厚度检测的实际需求,结合机器视觉、图像处理和嵌入式技术,设计与实现了一套基于高性能ARM11的微片状颗粒厚度检测系统。该系统以QT和S3C6410为软硬件平台,提出了利用轮廓提取和最小矩形边界框相结合的方法计算片状颗粒厚度。结果表明,该检测系统具有处理速度快,测量精度高和成本低廉等优点,满足了对颗粒厚度测量的需求。  相似文献   
132.
Image preview is a convenient way to browse large or multiple images on small displays. However, current signal-level image resampling algorithms may remove many features of interest in the preview image. In this paper, we propose perceptual image preview which retains more perceptual features such that users can inspect features of interest by viewing the preview image only and without zooming in. This technology has two components, structure enhancement and perceptual feature visualization. Structure enhancement enhances the image structure while suppressing subtle details using a gradient modulation method, thus making the succedent perceptual features more apparent. For perceptual feature visualization, features of interest detected in the picture is visualized on the structure enhanced preview image. We demonstrate with two examples of most commonly used image quality features, image blur and noise. The effectiveness of the proposed method is validated by experimental results.  相似文献   
133.
This paper presents an H infin fuzzy output-feedback tracking-control scheme for robotic manipulators without measuring joint velocities. The developed controller and observer are based on a fuzzy basis function network (FBFN), which is employed to approximate nonlinear functions in the dynamics of controller and observer. The FBFN-based observer that estimates joint velocities can remove the needs of full-state measurements. According to the inevitable approximation errors and external disturbances, an H infin auxiliary control signal is used to suppress the effects of the uncertainties. Moreover, all parameters of the fuzzy basis functions (FBFs) and FBF-to-output weights can be tuned online. The proposed controller requires no prior knowledge about the dynamics of the robot manipulator and no offline learning phase. Finally, comparative simulations on a three-link robot manipulator are provided to illustrate the tracking performance of the H infin FBFN-based output-feedback control approach.  相似文献   
134.
Genetic Algorithms (GAs) and other Evolutionary Algorithms (EAs), as powerful and broadly applicable stochastic search and optimization techniques have been successfully applied in the area of management science, operations research and industrial engineering. In the past few years, researchers gave lots of great idea for improvement of evolutionary algorithms, which include population initialization, individual selection, evolution, parameter setting, hybrid approach with conventional heuristics etc. However, though lots of different versions of evolutionary computations have been created, all of them have turned most of its attention to the development of search abilities of approaches. In this paper, for improving the search ability, we focus on how to take a balance between exploration and exploitation of the search space. It is also very difficult to solve problem, because the balance between exploration and exploitation is depending on the characteristic of different problems. The balance also should be changed dynamically depend on the status of evolution process. Purpose of this paper is the design of an effective approach which it can correspond to most optimization problems. In this paper, we propose an auto-tuning strategy by using fuzzy logic control. The main idea is adaptively regulation for taking the balance among the stochastic search and local search probabilities based on the change of the average fitness of parents and offspring which is occurred at each generation. In addition, numerical analyses of different type optimization problems show that the proposed approach has higher search capability that improve quality of solution and enhanced rate of convergence.  相似文献   
135.
136.
Supervisory control using variable lookahead policies   总被引:1,自引:1,他引:0  
This paper deals with the efficient on-line calculation of supervisory controls for discrete event systems (DES's) in the framework of limited lookahead control policies (or LLPs) that we introduced in previous papers. In the LLP scheme, the control action after a given trace of events has been executed is calculated on-line on the basis of anN-step ahead projection of the behavior of the DES. To compute these controls, one must calculate after the execution of each event the supremal controllable sublanguage of a finite language with respect to another finite larger language. In our previous work, we showed how the required supremal controllable sublanguage calculation can be performed by using a backward dynamic programming algorithm over the nodes of the tree representation of these two languages. In this paper, we pursue the same approach for the calculation of LLP controls, but instead we adopt a forward calculation procedure over theN-level tree of interest. This forward procedure improves upon previous work by avoiding the explicit consideration of all the nodes of theN-level tree, while still permitting tree-to-tree recursiveness as enabled events are executed by the system. The forward search ends whenever a control decision can be made unambiguously or whenever the boundary of theN-level tree is reached, whichever comes first. This motivates the name Variable Lookahead Policy (or VLP) for this implementation of the LLP supervisory control scheme. This paper presents a general VLP algorithm and studies the properties of several special cases of it. The paper also discusses the implementation of the VLP algorithms and presents computational results regarding the application of these algorithms to a time-varying DES.  相似文献   
137.
白蚁提取液急性毒性及致突变性研究   总被引:1,自引:0,他引:1  
本文采用大,小鼠急性经口毒性试验、Ames试验、小鼠骨髓细胞微核试验及小鼠精子畸变试验对白蚁提取液的毒理学安全性进行了研究,结果表明,白蚁提取液大,小鼠急性经口LD50均大于10g/kg体重,属“实际无毒”:体内(包括体细胞和生殖细胞)、体外致突变性试验系统均未检出其致突性。  相似文献   
138.
Statistical analysis of microhardness variations in thermal spray coatings   总被引:6,自引:0,他引:6  
A thermal barrier coating system consisting of a NiCoCrAlY bond coat and cerium-stabilized zirconia ceramic coating was sprayed on to a metallic substrate. Ageing at 400 and 800°C for 100, 500, and 1000 h was performed. Microhardness measurements of as-sprayed and heat-treated samples were used to evaluate microstructural variations throughout the thermally sprayed coating after different ageing conditions. Forty readings were taken at both the bond coat and ceramic coating positions within the thermal barrier coating (TBC) system and adjusted by subtracting the two largest and two smallest readings. Both data sets were statistically analysed to assess whether they belonged to Weibull or Gaussian (or normal) distributions. This study has established that the homogeneity of coatings, at least as measured by a microhardness test, varies during service and, thus, may influence the lifetime.Nomenclature Confidence limit - Mean value - Standard deviation - 2 Variance - Weibull modulus obtained from any method - Characteristic value obtained from any method - CV Coefficient of variation - f(x) Probability density function - F(x) Cumulative density function - i ith order in ascending data set - L Log-likelihood function - m Weibull modulus - n Total number of data points - x Microhardness data - x i Microhardness data which is ith order in ascending data set - x 0 Characteristic value which gives 63.2% cumulative density  相似文献   
139.
Wang  Lin  Wang  Xin  Li  Tao  Zheng  Ruijuan  Zhu  Junlong  Zhang  Mingchuan 《Neural computing & applications》2023,35(11):8051-8063
Neural Computing and Applications - Adaptive (sub)gradient methods have received wide applications such as the training of deep networks. The square-root regret bounds are achieved in convex...  相似文献   
140.
Lin  Yijun  Wu  Fengge  Zhao  Junsuo 《Neural computing & applications》2023,35(11):8227-8241
Neural Computing and Applications - High-resolution (HR) remote sensing images provide rich information for human activities. However, processing entire HR images is time-consuming, and many...  相似文献   
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