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1.
The heat pipe- radiator is a complex nonlinear system and may be prone to instability and oscillatory behaviors. In the paper, a fuzzy controller is designed and simulated exclusively to control it with a new-type function of contraction-expansion factor. It is applied successfully in decreasing temperature undulation and energy wasting by Matlab.  相似文献   

2.
The Internet technology has already changed the Information Society in profound ways, and will continue to do so. Nowadays many people foresee that there is a similar trajectory for the next generation of Internet - Grid Technology. As an emerging computational and networking infrastructure, Grid Computing is designed to provide pervasive, uniform and reliable access to data, computational and human resources distributed in a dynamic, heterogeneous environment. On the other hand, the development of Geographic Information System (GIS) has been highly influenced by the evolution of information technology such as the Internet, telecommunications, software and various types of computing technology. In particular, in the distributed GIS domain, the development However, due to the closed and centralized has made significant impact in the past decade. legacy of the architecture and the lack of interoperability, modularity, and flexibility, current distributed GIS still cannot fully accommodate the distributed, dynamic, heterogeneous and speedy development in network and computing environments. Hence, the development of a high performance distributed GIS system is still a challenging task.
So, the development of Grid computing technology undoubtedly provides a unique opportunity for distributed GIS, and a Grid Computing based GIS paradigm becomes inevitable. This paper proposes a new computing platform based distributed GIS framework - the Grid Geographic Information System (G^2IS).  相似文献   

3.
New conditions are derived for the l2-stability of time-varying linear and nonlinear discrete-time multiple-input multipleoutput (MIMO) systems, having a linear time time-invariant block with the transfer function F(z), in negative feedback with a matrix of periodic/aperiodic gains A(k), k = 0,1, 2,... and a vector of certain classes of non-monotone/monotone nonlinearities φp(-), without restrictions on their slopes and also not requiring path-independence of their line integrals. The stability conditions, which are derived in the frequency domain, have the following features: i) They involve the positive definiteness of the real part (as evaluated on |z| = 1) of the product of Г (z) and a matrix multiplier function of z. ii) For periodic A(k), one class of multiplier functions can be chosen so as to impose no constraint on the rate of variations A(k), but for aperiodic A(k), which allows a more general multiplier function, constraints are imposed on certain global averages of the generalized eigenvalues of (A(k + 1),A(k)), k = 1, 2 iii) They are distinct from and less restrictive than recent results in the literature.  相似文献   

4.
5.
For virtually realizing the graphic realism display of DXF machine parts, in AutoCAD2007 graphic drawing environment, an interactive experimental method was taken to realize the display of graphic in DXF, which was taken as the data-exchanged interface and source. Based on depth analysis of DXF data structure, take one drawing of DXF lathe turning rotational part asthe test piece. By VC++6.0 programming, part's geometry information could be obtained. Through data processing, 3D data of the test piece could be generated, which is based on 2D data of DXF test piece. Then, OpenGL graphic processing technologies (light, material, texture, map, et al.) were applied on the 3D display of test piece from DXF files or program modules. Finally based on the test report, results of the system functions were shared to prove the realization of system design, and the feasibility of algorithms used. In the developed software, Machine Designers could get a full view of machine parts, and do some proper modifications. The study content and results of our work have some theory and practical significance on the application of program design in the practical projects.  相似文献   

6.
This paper proposes a new different spectral density from power spectrum density of second order processes, thus we can get a new concept of stable white noise based on covariation function and covariation spectrum density. And a new technique is suggested for the estimation of the parameters of polynomial autoregressive (PAR) nonlinear colored noise processes with stable white noise excitations. Simultaneously, a simple whitening method is employed for polynomial autoregressive nonlinear stable colored noise.  相似文献   

7.
By combining training content with Game AI, Game Style Training can provide a rich, interactive and engaging educational substance. It supports experiential learning-bydoing. And it can contribute to promote interest and motivation of trainees. In this paper, a Context-Awareness Approach (CAA) is put forward for earthquake rescue training by applying the concept of ambient intelligence. The CAA takes advantage of player profile to monitor player states, utilizes time sensor and location sensor to supervise environment changes. And then, a Reinforcement Learning model based on MAS is designed to update game AI system.  相似文献   

8.
Fluid industry's production takes on high complexity, strong association, non-linear and indeterminacy. To find important parameters which influence production process, provide theoretical basis for process control of fluid industry's production and make the production process control more exact, we propose a flexible neural tree model in this paper. The model can be created based on predeflned information set. The structure and parameters of flexible neural tree are optimized by probabilistic incremental program evolution and simulation annealing respectively. We take production process of decomposed kiln---one of important cement's processes---as an example. The result indicates that the proposed model is greatly efficient.  相似文献   

9.
Owing to the enormous information and complex structure, video semantic processing is a tricky issue all along. Current researches are restricted within recognizing relative simple semantic in some certain domains. This paper brings forward a novel method transiting low-level feature to high-level semantic with Markov chain by stages, which takes object semantic as the core. This method is valid for recognizing complex event semantic. Semantic concept mapping mechanism based on semantic template is presented to realize the automatic recognition of video semantic. In the experiment contrasting with IBM's IMAT, our method shows more extensive recognition range and higher accuracy. Experimental results are encouraging, and indicate that the performance of the proposed approach is effective.  相似文献   

10.
Not only does business performance serve a major indicator for investors' decision, but it also has a lot to do with employees' living. Generally speaking, when predicting or analyzing business performance classification, most researchers adopt corporate financial early-warning or credit rating models, which pretty much use previous data and facts. Therefore, this paper brings about an alternative method to discriminate between excellent and poor business management, so as to take preventive measures prior to business crisis or bankruptcy. We collect the financial reports and financial ratios from the listed firms in mainland China and Taiwan as our samples to build up tbur kinds of forecasting models for business performance. The empirical results show that the GAANFIS model provides better classification forecasting capability than other models do while ANFIS model adjusted by genetic algorithm could effectively enhance the classification forecasting capability.  相似文献   

11.
Repetitious simulation after modifying parameters of multi-domain physical system based on Modelica often appears in model experiment and optimization design. At present, the solvers based on Modelica need calculate all the coupled blocks during every simulation run after updating parameters. Based on discussing scale decomposition methods of simulation model, subdivision solving strategy and minimum solving strategy are put forward to improve the efficiency of repetitious simulation, by which the numerical solution of the simulation model can be achieved by only calculating the solving sequence influenced by altered parameters. A simplified model of aircraft is used to demonstrate the efficiency of the strategies presented.  相似文献   

12.
A new affective model is presented, developed by fuzzy mathematics based on the differential emotions theory, in the model, human emotion and personality trait we defined is presented with fuzzy sets, and an emotion change equation to depict the change of human emotion. The equation includes the factors that affect human emotion, such as stimulus, personality trait and the fading of emotion. The paper develops a model that can simulate the human emotion better, and offers a new thinking for the research of artificial emotion.  相似文献   

13.
Due to severely constrained energy, storage capacity and computing power for nodes in wireless sensor network, the routing protocols have become a hot research topic. Directed diffusion is a communication paradigm for information dissemination in sensor networks based on data-centric routing. An energy efficient hybrid adaptive clustering for directed diffusion is presented in the paper. The main goal is to curb the interests flooding overhead by clustering. Hybrid of active and passive clustering creation is used to make tradeoff between maintenance cost and delay. The adaptive turning off the radio of redundant nodes and rotation of cluster heads is used to save energy. The ns-2 simulating results show that the protocol has good performances in energy consuming, delivery ratio and delay without leading to too much overhead comparing with existing directed diffusion protocols.  相似文献   

14.
The traditional strategy of 3D model reconstruction mainly concentrates on orthographic projections or engineering drawings. But there are some shortcomings. Such as, only few kinds of solids can be reconstructed, the high complexity of time and less information about the 3D model. The research is extended and process card is treated as part of the 3D reconstruction. A set of process data is a superset of 2D engineering drawings set. The set comprises process drawings and process steps, and shows a sequencing and asymptotic course that a part is made from roughcast blank to final product. According to these characteristics, the object to be reconstructed is translated from the complicated engineering drawings into a series of much simpler process drawings. With the plentiful process information added for reconstruction, the disturbances such as irrelevant graph, symbol and label, etc. can be avoided. And more, the form change of both neighbor process drawings is so little that the engineering drawings interpretation has no difficulty; in addition, the abnormal solution and multi-solution can be avoided during reconstruction, and the problems of being applicable to more objects is solved ultimately. Therefore, the utility method for 3D reconstruction model will be possible. On the other hand, the feature information in process cards is provided for reconstruction model. Focusing on process cards, the feasibility and requirements of Working Procedure Model reconstruction is analyzed, and the method to apply and implement the Natural Language Understanding into the 3D reconstruction is studied. The method of asymptotic approximation product was proposed, by which a 3D process model can be constructed automatically and intelligently. The process model not only includes the information about parts characters, but also can deliver the information of design, process and engineering to the downstream applications.  相似文献   

15.
In order toovercomethe poor local search ability of genetic algorithm, resulting in the basic genetic algorithm is time-consuming, and low search abilityin the late evolutionary, we use thegray coding instead ofbinary codingatthebeginning of the coding;we use multi-point crossoverto replace the originalsingle-point crossoveroperation.Finally, theexperimentshows that the improved genetic algorithmnot only has a strong search capability, but also thestability has been effectively improved.  相似文献   

16.
An adaptive image watermarking algorithm based on Watson's perceptual model is proposed in this paper. The proposed watermarking algorithm fully considers image regional characteristic. First, the cover image is divided into different smooth regions according to its gray value. Then watermark adjustment factors of those different regions are calculated respectively based on Watson's perceptual model. The watermark is embedded by the adjustment factors at last. Experiments show that the proposed algorithm has excellent imperceptibility and has little influence upon the eigenvalue of the cover image.  相似文献   

17.
Distinguishing with traditional tooth profile of spiral bevel and hypoid gear, it proposed a new tooth profile namely the spherical involute. Firstly, a new theory of forming the spherical involute tooth profile was proposed. Then, this theory was applied to complete parametric derivation of each part of its tooth profile. For enhancing the precision, the SWEEP method used for formation of each part of tooth surface and G1 stitching schema for obtaining a unified tooth surface are put forward and made the application in the accurate modeling. Lastly, owing to the higher accuracy of tooth surface of outputted model, it gave some optimization approaches. Given numerical example about the model can show that this designed gear with spherical involute tooth profile can achieve fast and accurate parametric modeling and provide a foundation for tooth contact analysis (TCA) in digitized design and manufacture.  相似文献   

18.
Recently there have been researches about new efficient nonlinear filtering techniques in which the nonlinear filters generalize elegantly to nonlinear systems without the burdensome lineafization steps. Thus, truncation errors due to linearization can be compensated. These filters include the unscented Kalman filter (UKF), the central difference filter (CDF) and the divided difference filter (DDF), and they are also called Sigma Point Filters (SPFs) in a unified way. For higher order approximation of the nonlinear function. Ito and Xiong introduced an algorithm called the Gauss Hermite Filter, which is revisited in [5]. The Gauss Hermite Filter gives better approximation at the expense of higher computation burden, although it's less than the particle filter. The Gauss Hermite Filter is used as introduced in [5] with additional pruning step by adding threshold for the weights to reduce the quadrature points.  相似文献   

19.
In MISO-OFDM system, ICI which is caused by frequency offset and phase noise breaks down orthogonality between sub-carriers and degrades system performance. In this paper, to compensate integrated effect of frequency offset and phase noise, several ICI self-cancellation methods are proposed; and CPE, ICI and CIR are derived theoretically in MISO-OFDM system. As results, by choosing several ICI self-cancellation methods appropriately, considerable performance improvement can be achieved in the MISO-OFDM system which affected by frequency offset and phase noise.  相似文献   

20.
The existing E-government systems in China are always tight coupling, which are difficult to be replanted and adapted to the new EG business requirements. The paper schemes out an On-Demand architecture for E-government System. It discusses the process macro point of view. As for of the "On-Demand" design in macro Service On Demand (macro-SOD), it applies the theoretical thoughts of SOA (Service Oriented Architecture), that is "services oriented", into the encapsulation of system functional components. In the paper, we discuss the divisions and the main types of macro EG ser'Aces. The new system works more efficiently with characters of loose coupling, reusable components, dynamic application integration, dynamic workflow modeling and etc. The researching fruits will benefit the application theories of information system's design and solve the problems of existing EG systems.  相似文献   

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