排序方式: 共有32条查询结果,搜索用时 17 毫秒
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Shima Eshaghi Hamed Kharrati Mohammad Ali Badamchizadeh Iraj Hasanzadeh 《International Journal of Control, Automation and Systems》2012,10(3):574-581
In this paper a hybrid control strategy is presented based on Dynamic Matrix Control (DMC) and feedback linearization methods for designing a predictive controller of five bar linkage manipulator as a MIMO system (two inputs and two outputs). Analyzing the internal dynamic of robot shows the open loop system is unstable and non-minimum phase, so in order to apply the predictive controller, special modifications are needed. These modifications on non-minimum phase behavior are performed using feedback linearization procedure based on state space realization. The design objective is to track a desirable set point as well as time varying trajectories as a command references with globally asymptotical stabilization. The proposed controller is applied to nonlinear fully coupled model of the typical five bar linkage manipulator with non-minimum phase behavior. Simulation results show that the proposed controller has good efficiency. The step responses of system with and without feedback linearization process illustrated that the mentioned modification for stabilizing is performed properly. After applying the proposed predictive controller, the joint angle of robot tracks the reference input while another input acts as the disturbance and vice versa. 相似文献
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In this work, Fe-doped (1?wt%) TiO2 loaded on the activated carbon nano-composite was prepared using a sol-gel method. A prepared nano-composite was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), BET surface area, Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL) spectroscopy and UV–Vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity of the nano-composite was evaluated through degradation of synthetic textile wastewater, reactive red 198, under visible light irradiations. The XRD result indicated that the TiO2 nano-composite contained only anatase phase. The surface area of the TiO2 increased from 48?m2/g to 100?m2/g through the fabrication of the nano-composite. The FE-SEM results indicate that the TiO2 particles with an average particle size of 35–70?nm can be deposited homogeneously on the activated carbon surface. DRS showed that the Fe doping in the TiO2 -activated carbon nano-composite induced a significant red shift of the absorption edge and then the band gap energy decreased from 3.3 to 2.9?eV. Photocatalytic results indicated that the photocatalytic activity of the Fe doped TiO2 increased under visible light irradiation in the presence of the activated carbon. 相似文献
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Moharramnejad Mojtaba Ehsani Ali Malekshah Rahime Eshaghi Shahi Mehrnaz Bavandpour Razieh Rajabi Hamidreza Mojab Seyyed Mohammadreza 《Journal of Materials Science: Materials in Electronics》2022,33(25):19693-19710
Journal of Materials Science: Materials in Electronics - This review gives an overview of the synthesis, surface, and electrochemical investigations over Mn-based compounds in the development of... 相似文献
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Akbar Eshaghi Amir Dashti Ameneh Eshaghi Reza Mozaffarinia 《Materials Science-Poland》2011,29(1):22-28
In this work, TiO2 and TiO2-SiO2 thin films on glass substrates were prepared by the sol-gel dip coating process. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to evaluate the structural and chemical properties of the films. The super-hydrophilicity was assessed by water contact angle measurement. XRD measurements confirmed the presence of polycrystalline anatase and rutile phases in the films. The water contact angle measurements showed that addition of SiO2 has a significant effect on the super-hydrophilicity of TiO2 thin films, especially if they are stored in a dark place. 相似文献
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In this paper we study a multi-product lot streaming problem in a stochastic job shop with equal and discrete sublots. The problem involves splitting order quantities of different products into different number of equal sublots (NES) and analyzing the effects of sublot-related transportation queue disciplines (TRQD) for different performance measures. Our simulation results show that some combination of TRQD and NES alternatives are appropriate for some performance measures. We also propose a simple heuristic to determine the NES of each product type to further improve the values of performance measures. 相似文献
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This paper, presents a robust voice activity detection (VAD) technique based on wavelet packet. In this technique sub-bands and their amplitudes are represented as the vectors for each sample time in order to find a new feature from the frequency and amplitude changes. On the other hand, the multi-resolution analysis property of the wavelet packet transform (WPT), the voiced, unvoiced, and transient components of speech can be distinctly discriminated. Then, a new feature extraction method is implemented based on observations of the angles between vectors. This feature extraction method retains most unvoiced sounds in a voice active frame. Experimental results show that the proposed WT feature parameter can extract the speech activity under poor SNR conditions and that it is also insensitive to variable-level of noise. 相似文献
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Studies on health domain have shown that health websites provide imperfect information and give recommendations which are not up to date with the recent literature even when their last modified dates are quite recent. In this paper, we propose a framework which assesses the timeliness of the content of health websites automatically by evidence based medicine. Our aim is to assess the accordance of website contents with the current literature and information timeliness disregarding the update time stated on the websites. 相似文献
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Prediction of wheat quality parameters using near-infrared spectroscopy and artificial neural networks 总被引:1,自引:0,他引:1
Ayse C. Mutlu Ismail Hakki Boyaci Huseyin E. Genis Rahime Ozturk Nese Basaran-Akgul Turgay Sanal Asuman Kaplan Evlice 《European Food Research and Technology》2011,233(2):267-274
In wheat and flour processing, the quality control needs quick analytical tools for predicting physical, rheological, and
chemical properties. In this study, near infrared reflectance (NIR) spectroscopy combined with artificial neural network (ANN)
was used to predict the flour quality parameters that are protein content, moisture content, Zeleny sedimentation, water absorption,
dough development time, dough stability time, degree of dough softening, tenacity (P), extensibility (L), P/G, strength, and
baking test (loaf volume and loaf weight). A total of 79 flour samples of different wheat varieties grown in different regions
of Turkey were chemically analyzed, and the results of both NIR spectrum (400–2,498 nm) and chemical analysis were used to
train/test the network by applying various ANN architectures. Prediction of protein, P, P/G, moisture content, Zeleny sedimentation,
and water absorption in particular gave a very good accuracy with coefficient of determination (R
2) of 0.952, 0.948, 0.933, 0.920, 0.917, and 0.832, respectively. The results indicate that NIR combined with the ANN can successfully
be used to predict the quality parameters of wheat flour. 相似文献