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2.
In order to solve the mismatched uncertainties of a class of nonlinear systems,a control method of sliding mode control (SMC) based on the backstepping design is proposed. It introduces SMC in to the last step of backstepping design to modify the backstepping algorithm. This combination not only enables the generalization of the backstepping design to be applied to more general nonlinear systems, but also makes the SMC method become effective in solving the mismatched uncertainties. The SMC based on the backstepping design is applied to the flight control system design of an aerodynamic missile. The control system is researched through simulation. The simulation results show the effectiveness of the proposed control method. 相似文献
3.
With developments in science and technology, product innovation is the key to enterprise performance in the competitive market. In consumer demand-oriented modern product design, effectively combining product design with the esthetic perceptions and preferences of consumers is a problem that urgently needs to be addressed. However, the traditional design method is completely dominated by designers without user participation. The purpose of this study was to give designers an impetus for restructuring and upgrading a design. A gene network design model was developed with the advantages of a gene network and neural network. This allowed the target elements of a product design to be obtained using a nonlinear network. Finally, a case study was used to show the detailed procedure of the design model. To reveal the advantages of the proposed model, it was compared with other methods such as a gene-based design method, an emotional design method, and a fuzzy Kano design method. The results showed that the proposed model was more efficient and scientific, and provided consumers with a multidimensional evaluation system to determine the optimal design schemes. 相似文献
4.
In this paper, we have proposed a hybrid denoising algorithm based on combining of the shearlet transform method, as a pre-processing step, with the Yaroslavsky’s filter, as a kernel smoother, on a wide class of images with various properties such as thin features and textures. In the other word, proposed algorithm is a two-step algorithm, where in the first step the image is filtered by shearlet transform method and in the second step the weighted Yaroslavsky’s filter is applied on result of first step. The weight coefficients of the Yaroslavsky’s filter are achieved by pixel similarities in the denoised image from the first step. The theoretical results are confirmed via simulations for 2D images corrupted by additive white Gaussian noise. Experimental results illustrate that proposed hybrid method has good effect on suppressing the pseudo-Gibbs and shearlet-like artifacts can obtain better performance in terms of mean square error (MSE), peak signal to noise ratio (PSNR) and structural similarity (SSIM) index rather than existing state-of-the-art methods. 相似文献
5.
Speech signal processing and its recognition system have gained a lot of attention from last few years due to its widespread application. In this paper, a novel approach is proposed for diagnosis and monitoring the Parkinson’s Disease (PD) which is the second most severe neurological disease in the world. PD is a neurodegenerative disease which impairs person’s balance, motor skills, speech, and other characteristics such as decision making process, emotions, and sensation. Here, we proposed a cloud based framework for detecting and monitoring Parkinson patients that will enable healthcare service in low resource setting. In the developing countries, where most of the people do not get proper healthcare services and are not well aware of Parkinson’s disease, let alone detecting and getting healthcare for PD, this system can be very practical and useful. For this system, the patients of rural areas, patients from the regions where doctors are not available, can communicate to the doctors only if they have internet connections in their smart phones to access the cloud. Doctors can check and detect patient’s PD by checking their voice disorders or Dysphonia over cloud. With this system, a PD patient can be easily detected and diagnosed by giving their voice samples through their phones, regardless of their location. Based on the evaluation, our proposed systems are avail to achieve 96.6% accuracy in the cloud environment for detecting PD. It is expected that the proposed framework will have great potential to enable healthcare service for PD patients, who live in remote areas, especially in developing countries. 相似文献
6.
A novel image encryption algorithm based on the Rubik’s cube scrambling is proposed in this paper to achieve simultaneous encryption of a group of images. This proposed encryption algorithm begins with chaotic Baker map permutation with a selected mode of operation or RC6 algorithm as a first step for encrypting the images, separately. After that, the obtained encrypted images are further encrypted in a second stage with Rubik’s cube. Chaotic or RC6 encrypted images are used as the faces of the Rubik’s cube. From the concepts of image encryption, the RC6 algorithm adds a degree of diffusion, while chaotic Baker map adds a degree of permutation. The Rubik’s cube algorithm adds more permutation to the encrypted images, simultaneously. The simulation results demonstrate that the proposed encryption algorithm is efficient, and it exhibits strong robustness and security. The encrypted images are further transmitted over a wireless channel with Orthogonal Frequency Division Multiplexing (OFDM) system, and decrypted at the receiver side. Evaluation of the quality of the decrypted images at the receiver side reveals good performance. 相似文献
7.
Parkinson’s disease (PD) is often responsible for difficulties in interacting with smartphones; however, research has not yet addressed these issues and how these challenge people with Parkinson’s (PwP). This paper specifically investigates the symptoms and characteristics of PD that may influence the interaction with smartphones to then contribute in this direction. The research was based on a literature review of PD symptoms, eight semi-structured interviews with healthcare professionals and observations of PwP, and usability experiments with 39 PwP. Contributions include a list of PD symptoms that may influence the interaction with smartphones, a set of experimental results that evaluated the performance of four gestures tap, swipe, multiple-tap, and drag and 12 user interface design guidelines for creating smartphone user interfaces for PwP. Findings contribute to the work of researchers and practitioners’ alike engaged in designing user interfaces for PwP or the broader area of inclusive design. 相似文献
8.
The implementations of design for assembly and design for manufacture (DFM) led to enormous benefits including simplification of products, reduction of assembly and manufacturing costs, improvement of quality, and reduction of time to market. More recently, environmental concerns required that disassembly and recycling issues should be considered during the design stages. The effort to reduce total life-cycle costs for a product through design innovation is becoming an essential part of the current manufacturing industry. Therefore, researchers begin to focus their attention on design for environment, design for recyclability, design for life-cycle (DFLC), etc. These studies are sometimes referred to as Design for X (DFX). Since the late 1990s, hundreds of papers have been published pertaining to DFX applications in manufacturing. Most of them are widely distributed over many different disciplines and publications. This makes it very difficult for one to locate all the information necessary for the application of DFX in manufacturing. A paper that can help researchers and practitioners applying this emerging technology is highly desirable. The objective of this paper is to present the concepts, applications, and perspectives of ‘DFX’ in manufacturing, thus providing some guidelines and references for future research and implementation. 相似文献
9.
We introduce a hierarchical approach for secure multicast where rekeying of groups of users is made through a method based on Euclid’s algorithm for computing GCD. We consider tree arrangements of users that decrease requirements on bandwidth as protocols of the same nature, but also show that computational requirements are less than in other similar approaches. We also introduce a distributed protocol by groups with group managers that not only helps to decrease size of rekeying messages with respect to a centralized approach, but also to increase the security level concerning authentication of users and distributed information. 相似文献
11.
The present work summarizes the efforts made to design a set of digital filters amenable of emulating the frequency selectivity of the inner ear, through the application of a set of common techniques in the field of digital signal processing, viz. Padé's approximation. It is shown that the resulting set of digital filters is realizable, stable and causal, and reproduces the elementary characteristics in time and frequency of a real auditory system at a reasonably low computational cost, which renders the model amenable for its use in the design of VLSI circuitry to substitute or complement human hearing, and for speech processing. 相似文献
12.
A sensor suitable for online monitoring of viscosity and density of glycerol–water mixtures is presented. The device is based on Lorentz force excitation and features an integrated piezoresistive readout. The core sensing element is a rectangular vibrating plate suspended by four beam springs. Two of the plate-carrying springs comprise piezoresistors. With two additional resistors on the silicon rim they form a half Wheatstone-bridge. Through the conductive layer of the beam springs a sinusoidal excitation current is driven. In the field of a permanent magnet, the Lorentz force excites plate vibrations resulting in a bridge unbalance. We recorded both the frequency response of the amplitude and the phase of the bridge output. By evaluating the properties of the resonant system, it is possible to extract the glycerol percentage and, hence, the viscosity and the mass density of the mixtures. 相似文献
13.
Silicon carbide (SiC) is a promising material for applications in harsh environments. Standard silicon (Si) microelectromechanical systems (MEMS) are limited in operating temperature to temperatures below 130°C for electronic devices and below 600°C for mechanical devices. Due to its large bandgap SiC enables MEMS with significantly higher operating temperatures. Furthermore, SiC exhibits high chemical stability and thermal conductivity. Young’s modulus and residual stress are important mechanical properties for the design of sophisticated SiC-based MEMS devices. In particular, residual stresses are strongly dependent on the deposition conditions. Literature values for Young’s modulus range from 100 to?400?GPa, and residual stresses range from 98 to?486?MPa. In this paper we present our work on investigating Young’s modulus and residual stress of SiC films deposited on single crystal bulk silicon using bulge testing. This method is based on measurement of pressure-dependent membrane deflection. Polycrystalline as well as single crystal cubic silicon carbide samples are studied. For the samples tested, average Young’s modulus and residual stress measured are 417?GPa and 89?MPa for polycrystalline samples. For single crystal samples, the according values are 388?GPa and 217?MPa. These results compare well with literature values. 相似文献
14.
The article concerns the problem of detecting masqueraders in computer systems. A masquerader in a computer system is an intruder who pretends to be a legitimate user in order to gain access to protected resources. The article presents an intrusion detection method based on a fuzzy approach. Two types of user’s activity profiles are proposed along with the corresponding data structures. The solution analyzes the activity of the computer user in a relatively short period of time, building a user’s profile. The profile is based on the most recent activity of the user, therefore, it is named the local profile. Further analysis involves creating a more general structure based on a defined number of local profiles of one user, called the fuzzy profile. It represents a generalized behavior of the computer system user. The fuzzy profiles are used directly to detect abnormalities in users’ behavior, and thus possible intrusions. The proposed solution is prepared to be able to create user’s profiles based on any countable features derived from user’s actions in computer system (i.e., used commands, mouse and keyboard data, requested network resources). The presented method was tested using one of the commonly available standard intrusion data sets containing command names executed by users of a Unix system. Therefore, the obtained results can be compared with other approaches. The results of the experiments have shown that the method presented in this article is comparable with the best intrusion detection methods, tested with the same data set, in the matter of the obtained results. The proposed solution is characterized by a very low computational complexity, which has been confirmed by experimental results. 相似文献
15.
The Journal of Supercomputing - Dockless bike-sharing is more and more popular all over the world, which enables passengers to choose destinations more flexibly, so that the transfer radius between... 相似文献
16.
The intelligent machine vision technology based on man-machine interaction mode has the advantages of weak intrusion, low adhesion and no device binding. With the development and progress of science and technology, the intelligent machine vision technology has become one of the most important directions in the field of human–computer interaction. Compared with the traditional interactive mode, the intelligent machine vision interaction technology is quite convenient, and the existence of these problems can also influence the vision of the intelligent machine to a certain extent. And the wide application of the sense interaction. At present, the operation precision is the main basis of the machine vision interaction design. Therefore, this paper studies the precision of the visual interaction of the intelligent machine. In this paper, three point-to-click experiments will be carried out on the basis of the Fitts' Law. The accuracy of the machine vision algorithm is experimentally studied from the operating direction, the mapping scale equation and the machine vision algorithm, and a reasonable suggestion is made for the intelligent machine vision interactive design of the human interaction mode. 相似文献
17.
In recent years micro electro mechanical system (MEMS) based micro resonant sensors have been given a lot of attention due to their potential as a platform for the development of many novel physical, chemical, and biological sensors. That is why this paper covers post processing of the structures fabricated through Multi-Project-Wafer using 0.35 µm MIMOS CMOS technology with particular focus on dry etching of Si and SiO 2 from the front side of CMOS–MEMS chip that is optimized using aluminum coated carrier wafer and achieved results are debris free as compared to photoresist coated carrier wafer. The device is etched through from the front side to avoid parasitic capacitances and squeeze film damping by keeping minimum size of the die. The etching of SiO 2 as well as deep Si etch-through using the same plasma etcher (SS110A Tegal) is successfully demonstrated in this work. Finally, after the successful post CMOS micromachining of the device, resonance frequency i.e. 8164 Hz and quality factor i.e. 51.34, is determined. The joule heating effect due to the passing of current through the central shuttle of the device is characterized. The maximum temperature close to the anchors of the comb resonator where the piezoresistors are located is determined through temperature coefficient of resistance measurement using PE-4RF type probe station and it is found to be 37.62 °C. 相似文献
18.
One of the most important research topics in Information Retrieval is term weighting for document ranking and retrieval, such as TFIDF, BM25, etc. We propose a term weighting method that utilizes past retrieval results consisting of the queries that contain a particular term, retrieval documents, and their relevance judgments. A term’s Discrimination Power(DP) is based on the difference degree of the term’s average weights obtained from between relevant and non-relevant retrieved document sets. The difference based DP performs better compared to ratio based DP introduced in the previous research. Our experimental result shows that a term weighting scheme based on the discrimination power method outperforms a TF*IDF based scheme. 相似文献
19.
Microsystem Technologies - To obtain accurate demodulation of the spinning frequency of MEMS carrier-driven gyro output signal, a frequency estimation algorithm combining the real and imaginary... 相似文献
20.
This paper proposes a differential evolution algorithm based on ε-domination and orthogonal design method (ε-ODEMO) to solve power dispatch problem considering environment protection and saving energy. Besides the operation costs of thermal power plant, contaminative gas emission is also optimized as an objective. In the proposed algorithm, ε-dominance is adopted to make genetic algorithm obtain a good distribution of Pareto-optimal solutions in a small computational time, and the orthogonal design method can generate an initial population of points that are scattered uniformly over the feasible solution space, these modify the differential evolution algorithm (DE) to make it suit for multi-objective optimization (MOO) problems and improve its performance. A test hydrothermal system is used to verify the feasibility and effectiveness of the proposed method. Compared with other methods, the results obtained demonstrate the effectiveness of the proposed algorithm for solving the power environmentally-friendly dispatch problem. 相似文献
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