An optimal method for nonlinear iterative learning control systems with constraint and model uncertainty

Clonal selection algorithm is improved and proposed as a method to implement nonlinear optimal iterative learning control algorithm. In the method, more priori information was coded in a clonal selection algorithm to decrease the size of the search space and to deal with constraint on input. Another clonal selection algorithm is used as a model modifying device to cope with uncertainty in the plant model. Finally, simulations show that the convergence speed is satisfactory regardless of the nature of the plant and whether or not the plant model is precise.     

Usage control mechanism for securing the multi-organizational grid

Security is a fundamental but challenging issue in the dynamic and multi-organizational computational grid. Focusing on the closed system, traditional access control model considered static authorization decisions based on pre-assigned permissions. To facilitate collaborations and interoperations across the grid, we propose a usage control mechanism for computational grid. Our mechanism is based on the usage control model. By leveraging continuous usage control on grid services and monitoring the status and behaviors of the subjects involved in the collaborations, our mechanism improves collaboration＇s security. Furthermore, our mechanism enables richer and finer-grained control over authorizations on resources and services involved in collaborations and interoperations than that of traditional access control mechanisms. Our mechanism can contribute to maintain the security and interests of the service providers in the grid environment.     

A differential evolutionary based algorithm for multiuser OFDMA system adaptive resource allocation

In this paper, the problems of radio resource allocation for Orthogonal Frequency Division Multiple Access （OFDMA） systems are addressed. The main goal of this paper is to present and analyze base station allocation of subcarriers and adaptive modulation. We impose a set of proportional fairness constraints to assure that each user can achieve a required data rate. Since the optimal solution to the fairness problem is extremely computationally complex to obtain, we propose an adaptive radio resource allocation method based on differential evolutionary algorithm for multiuser OFDMA system. The performance of the described schemes is further evaluated in numerical experiments. We improve the convergence of the differential evolutionary algorithm through the method of elitist selection and adding some individuals with ＇good＇ genes to the initial population. Simulation results show that out proposed algorithm better than static subcarrier allocation schemes TDMA in muhiuser OFDMA system.     

Topology control for directed diffusion in wireless sensor networks

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.     

Design of Fighter Flight Formation for Aerial Refueling Racetrack Mission with Drogue-Hose Configuration

The flying of aircraft information necessitates the extension of the theory of formation flight control to allow for three dimensional formation maneuvers. A leader and wingman formation is considered. A rotating reference frame attached to the wingman is used and special attention is given to the motion of the leader relative to the wingman. A thirteen state, three inputs, and three disturbances signal control system which models the dynamics of a two aircraft formation in three dimensional spaces is developed. The theory of formation control was applied to KC-130J tanker and F-16 receiver configuration to study the availability of performing such mission on a large scale. Three formation flight control concepts are investigated. A proportional, integral, and derivative automatic control system to maintain the wing aircraft in the specified formation geometry despite the leader＇s maneuvers is designed, and its performance is examined in simulation experiments. By adding special compensation to each control law to maintain the design damping ratio and gain margin, it is possible to reach the desired performance satisfying the predefined relative distances boundaries.     

Image Mosaic Techniques OptimizationUsing Wavelet

This essay concentrates on two key procedures of image mosaic--image registration and imagefusion.Becauseof the character of geometric transformation invariance of edge points, wecalculate the angle difference of the direction vector ofedge points in different images anddraw an angle difference histogramto adjust the rotationproblem. Through this way, algorithm based on gray information is expandedandcan be used in images withdisplacementand rotation. Inthe term of image fusion, wavelet multi-scale analysis is used to fuse spliced images. In order to choose the best method of imagefusion,weevaluate the results of different methods of image fusion by cross entropy.     

Hourglass Control in Dynamic Explicit Simulation of Cold Ring Rolling Process

Hourglass is remarkably aroused in ring rolling simulation with reduced integration element because of violent ring vibration and small contact area of ring with forming rollers. Hourglass energy can be reduced by improving mesh density. Combined approach of artificial damping and artificial stiffness can control the hourglass. A ring with rectangular section is simulated with the weight factor of artificial stiffness resistance set to 0.2. The artificial damping hourglass control coefficient is set to 0.1, and the artificial stiffness hourglass control coefficient is set to 0.001. The ratio of hourglass energy to internal energy is reduced to 2.5 percent. Compared with axial spread width test, the effectiveness of hourglass control in ring rolling simulation is verified.     

Utilizing MATLAB and SIMULINK in Graduate Course of Intelligent Control

Control system design packages like MATLAB, MATRIXX, Control C, SIMNON, etc. have become essential ingredients of both undergraduate and graduate courses in the fields of systems and controls. The use of MATLAB and its companion toolboxes in teaching graduate and undergraduate courses was reported by many educators in the past. The experience with the use of SIMULINK and MATLAB in Intelligent Control Course is introduced which is offered to graduate students at Beijing University of Aeronautics and Astronautics （BUAA）. The use of SIMULINK for simulation of intelligent control of their behavior is emphasized. The MATLAB features useful in this course are presented. How SIMULINK and MATLAB help in enhancing the students＇ understanding of the material and reducing the amount of time spent in performing computational homework assignments is discussed.     

On the ?2 stability of time varying linear and nonlinear discrete time MIMO systems

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.     

Context-awareness approach in game style application

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.     

Whitening of fractional order polynomial autoregressive Non-Gaussian impulsive stable colored noise

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.     

Conditions for Parametric and Geometric Coincidence of Two Rational Curves

Necessary and sufficient conditions for the relationship of weights and control points of two parametrically and geometrically coincident rational Bézier or NURBS curves are discussed in detail. The method is based on the reduction of matrices and transformation between rational Bézier curves and NURBS curves.     

Finite Element Analysis of Steam Turbine Diaphragm

Thediaphragmofsteam turbine isoneofthemainpartsofthepassageunitfor air flowing.For studying its working conditionand performance, the three-dimensionalfinite element model（FEM）with thesoftware ANSYS10.0 isestablished according to theactualworking parameters. With the model, the deformation resultsand stress field resultsare analyzed andthe maximum displacement and stress value are calculated, meanwhile,theircorrespondingpositions are found. It provides a good foundationfor solving the problem inproduction.     

Design and simulation of a nonlinear adaptive fuzzy controller for the heat pipe- radiator

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.     

DNA-chip-based dynamic broadcast encryption scheme with constant-size ciphertexts and decryption keys

In this paper we present DNA-DBE,a DNA-chip-based dynamic broadcast encryption scheme.In our scheme,new users can join dynamically without modification of other users’decryption keys.Either the ciphertext or the decryption key is of constant-size.Backward secrecy is achieved in DNA-DBE:if new users join the system dynamically,they will not be able to retrieve past data.The security of our scheme relies on hard biological problems,which are immune to attacks of new computing technologies in the future.There exists a special feature in DNA–based cryptosystems,i.e.the set of encryption keys and the set of decryption keys have a many-to-many relationship.The implementation of more complicated DNA cryptosystems taking advantage of this special feature has been previously left as an open problem.Our DNA-DBE system is a solution to this open problem,which is also the first exploration of DNA based group-oriented encryption system.     

Solving Strategy for Repetitious Simulation of Multi-domain Physical System Based on Modelica

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.     

Towards the processing breakdown of syntactic garden path phenomenon： A semantic perspective of natural language expert system

Processing breakdown involved in garden path phenomenon is a special phenomenon in which the processor has to backtrack on the early understanding and create another path out to process data successfully and perfectly. From the semantic viewpoint of Natural Language Expert System, this paper puts forward a particular schema by which processing procedure of breakdown can be shown clearly and raises a special matching pattern to demonstrate the activity of noun-verb category. According to the analysis of interactive presentation of same word in which noun and verb definitions are involved, it is verified that Natural Language Expert System, only when its semantic database is activated, can clear the misunderstanding of syntactic sentences in which processing breakdown appears.     

3D Model Reconstruction Based on Process Information

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.     

Quadrature Kalman Filter （QKF） and Reduced Quadrature Kalman Filter （R-QKF） in Ballistic Target Tracking

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.     

Accurate Modeling of the Spiral Bevel and Hypoid Gear with a New Tooth Profile

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.