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31.
Dong-Wei Chen Jian-Qiang Sheng Jun-Jie Chen Chang-Dong Wang 《Neural computing & applications》2014,25(7-8):1809-1822
Recently, as one of the most popular exemplar-based clustering algorithms, affinity propagation has attracted a great amount of attention in various fields. The advantages of affinity propagation include the efficiency, insensitivity to cluster initialization and capability of finding clusters with less error. However, one shortcoming of the affinity propagation algorithm is that, the clustering results generated by affinity propagation strongly depend on the selection of exemplar preferences, which is a challenging model selection task. To tackle this problem, this paper investigates the clustering stability of affinity propagation for automatically selecting appropriate exemplar preferences. The basic idea is to define a novel stability measure for affinity propagation, based on which we can select exemplar preferences that generate the most stable clustering results. Consequently, the proposed approach is termed stability-based affinity propagation (SAP). Experimental results conducted on extensive real-world datasets have validated the effectiveness of the proposed SAP algorithm. 相似文献
32.
《Journal of Process Control》2014,24(5):550-567
For many practical industrial spatially distributed processes (SDPs), their dynamics are usually described by highly dissipative nonlinear partial differential equations (PDEs). In this paper, we address the L2 disturbance attenuation problem of nonlinear SDPs using the Hamilton–Jacobi–Isaacs (HJI) approach. Firstly, by collecting an ensemble of PDE states, Karhunen–Loève decomposition (KLD) is employed to compute empirical eigenfunctions (EEFs) of the SDP based on the method of snapshots. Subsequently, these EEFs together with singular perturbation (SP) technique are used to obtain a finite-dimensional slow subsystem of ordinary differential equation (ODE) that accurately describes the dominant dynamics of the PDE system. Secondly, based on the slow subsystem, the L2 disturbance attenuation problem is reformulated and a finite-dimensional H∞ controller is synthesized in terms of the HJI equation. Moreover, the stability and L2-gain performance of the closed-loop PDE system are analyzed. Thirdly, since the HJI equation is a nonlinear PDE that has proven to be impossible to solve analytically, we combine the method of weighted residuals (MWR) and simultaneous policy update algorithm (SPUA) to obtain its approximate solution. Finally, the simulation studies are conducted on a nonlinear diffusion-reaction process and a temperature cooling fin of high-speed aerospace vehicle, and the achieved results demonstrate the effectiveness of the developed control method. 相似文献
33.
《Journal of Process Control》2014,24(8):1301-1310
Energy consumption by heating, ventilation, and air conditioning (HVAC) systems exhibits a clear correlation with electricity prices. The method of economic model predictive control (EMPC) can be used in conjunction with thermal energy storage (TES) to time-shift power consumption away from periods of high demand to periods of low energy cost. Dynamic electricity pricing and weather condition forecasts can be readily incorporated within this methodology. Unfortunately, the receding horizon nature of this control strategy makes it very susceptible to the quality of the forecasts used. To this end, the development and implementation of several forecasting methods will be discussed. Finally, the EMPC performance of these methods will be assessed on a simple building example using active TES. 相似文献
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36.
绿色水处理剂氢氧化镁应用的研究进展 总被引:1,自引:0,他引:1
氢氧化镁(氧化镁)被称为绿色安全的废水处理剂,本文评述了氢氧化镁在环境保护方面的研究与应用进展,包括工业废水中铅、铬、镍等重金属离子的去除和酸性废水的中和处理,并列举了氢氧化镁对一些实际废水的良好处理效果,包括其对一些特殊废水如含硼废水和放射性废水的处理效果,最后展望了其在生产和应用方面的发展前景。 相似文献
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38.
Dong Shu Jinghua Zhang Chun He Yuezhong Meng Hongyu Chen Yongsheng Zhang Mianping Zheng 《Journal of Applied Electrochemistry》2006,36(12):1427-1431
High electrocatalytic activity of an electropolymerized film of poly(3-methoxythiophene) (PMOT) is reported toward the redox reaction of 2,5-dimercapto-1,3,4-thiadiazole (DMcT) as a promising cathode material for the lithium ion battery. Cyclic voltammetry showed improved electrochemical performance of DMcT on PMOT-coated Pt electrode, indicating accelerated redox kinetics. Moreover, charge-discharge tests exhibited higher discharge capacity and slower capacity fading of the PMOT-doped DMcT composite cathode compared with pure DMcT. 相似文献
39.
Video frame-rate up-conversion is one of the common operations for tampering digital videos in the temporal domain, such as creating fake high-quality videos and splicing two video clips with different frame rates. However, few existing works have been proposed for detecting this form of tampering operation. Based on the analysis of extensive experiments, we found that frame-rate up-conversion algorithms employed in most current video editing softwares will inevitably introduce some periodic artifacts into inter-frame similarity in the resulting video frame sequence. By analyzing such artifacts, we propose a simple yet very effective method to expose video after frame-rate up-conversion, and further estimate its original frame rate. The experimental results evaluated on 100 original videos at different frame rates have shown the effectiveness of the proposed method. The average detection accuracy can achieve as high as 99 % on noise-free videos in uncompressed and H.264/AVC formats. Besides, the proposed method is robust to noise as the detection accuracy could reach over 85 % and 95 % on noised videos with Gaussian white noise when SNR is 33 db and 36 db respectively. 相似文献
40.
《Desalination》2007,202(1-3):293-301
In a Sino-German research project, a joined developed sustainable water reclamation concept was developed for different applications of municipal water reuse at the Olympic Green 2008. The concept combines advanced technological processes like membrane bioreactors, specific phosphorus (P) adsorption columns and ultrafiltration (UF) with nature-based treatment processes like wetland and bank filtration mechanisms. The project’s approach is not only to comply with the reclamation requests of the Olympic Green 2008, but also to give an example for better, adapted and energy efficient reuse applications throughout China. The study shows that fixed-bed granular ferric hydroxide (GFH) adsorbers after a membrane bioreactor (MBR) can maintain a total phosphorus (TP) concentration of <0.03 mg L−1. A low P concentration will be necessary to control eutrophication in the artificial Olympic Lake filled with treated wastewater. With an adsorption capacity of approx. 20 mg g−1 d.m. at a corresponding equilibrium concentration of 1 mg L−1 P, GFH reaches long operation times and can be repeatedly regenerated by caustic solutions with an efficiency of 50%. Apart from scenic impoundments, treated wastewater will be used for irrigation and toilet flushing. The latter requires a superior quality that will be delivered by low pressure UF treatment after lake (bank) filtration. A crucial reduction of fouling potential for dead-end UF is expected. 相似文献