ZrO_2/SiO_2溶胶-凝胶薄膜膜层间的渗透行为

分别以丙醇锆和正硅酸乙酯为原料,采用溶胶-凝胶工艺制备了性能稳定的ZrO2和SiO2溶胶。用旋转镀膜法在K9玻璃上分别制备了单层SiO2薄膜、单层ZrO2薄膜、ZrO2/SiO2双层膜和SiO2/ZrO2双层膜。采用原子力显微镜观察了薄膜的表面形貌,用椭偏仪测量薄膜的厚度与折射率,用紫外-可见光分光光度计测量了薄膜的透射率。对薄膜的透射光谱和椭偏仪模拟的数据进行分析,发现SiO2/ZrO2双层膜之间的渗透十分明显,而ZrO2/SiO2双层膜之间几乎不发生渗透。利用TFCalc模系设计软件,采用三层膜模型对薄膜的透射率进行模拟,得出的透射曲线与用紫外-可见光分光光度计测量的透射曲线十分符合。

Direct adaptive fuzzy control based on integral-type Lyapunov function

A new scheme of direct adaptive fuzzy controller for a class of nonlinear systems with unknown triangular control gain structure is proposed. The design is based on the principle of sliding mode control and the approximation capability of the first type fuzzy systems. By introducing integral-type Lyapunov function and adopting the adaptive compensation term of optimal approximation error, the closed-loop control system is proved to be globally stable, with tracking error converging to zero. Simulation results demonstrate the effectiveness of the approach.

Multilevel Power Modeling of Base Station and Its ICs

A new power estimation method is proposed for base station(BS) in this paper.Based on this method,a software platform for power estimation is developed.The proposed method models power consumption on different abstraction levels by splitting a typical base station into several basic components at different levels in the view of embedded system design.In particular,our focus is on baseband IC(Integrate Circuit) due to it's the dominant power consumer in small cells.Baseband power model is based on arithmetic computing costs of selected algorithms.All computing and storage costs are calibrated using algorithm complexity,hardware architecture,activity ratio,silicon technology,and overheads on all hierarchies.Micro architecture and IC technology are considered.The model enables power comparison of different types of base stations configured with different baseband algorithms,micro architectures,and ICs.The model also supports cellular operators in power estimation of different deployment strategies and transmission schemes.The model is verified by comparing power consumption with a real LTE base station.By exposing more configuration freedoms,the platform can be used for power estimation of current and future base stations.

Design and Implementation of Visualized Workflow Modeling System Based on B/S Structure

According to the necessity of flexible workflow management system, the solution to set up the visualized workflow modelling system based on B/S structure is put forward, which conforms to the relevant specifications of WfMC and the workflow process definition meta-model. The design for system structure is presented in detail, and the key technologies for system implementation are also introduced. Additionally, an example is illustrated to demonstrate the validity of system.

Design and dynamic simulation of hydraulic system of a new automatic transmission

A new hydraulic system of a novel automatic transmission (AT) was designed. The dimension and structure of valves and cylinders were designed by theoretical calculation. The dynamic simulation model of hydraulic system of AT was established by ITI-SimulationX. Simulation results and theoretical design results were compared to confirm the simulation model. Based on the confirmed simulation model, the simulation results of pressure and flow of the hydraulic system were analyzed. The dynamic simulation method is very helpful for designing and analyzing the performance of hydraulic system and further optimization design. The theoretical design method and dynamic simulation model are feasible for the real industrial applications. The research results can be used in hydraulic system design and optimization.

Model Study on a Submerged Catalysis/Membrane Filtration System for Phenol Hydroxylation Catalyzed by TS-1

This ranearch is focused on the, develonment of a simnle design model of the submerged catalysis/membrane filtration （catalysis/MF） system for phenol hydroxylation over TS-1 based on the material balance of the phenol under steady state and the reported kinetic studies. Based on the developed model, the theoretical phenol Conversions at steady state could be calculated using the kinetic parameters obtained from the previous batch experiments. The theoretical conversions are in good agreement with the experimental data obtained in the submerged catalysis/MF system within relative error of ±5%. The model can be used to determine the optimal experimental conditions to carry out the phenol hydroxylation over TS-1 in the submerged catalysis/MF system.

Model-based design method of two-axis four-actuator fast steering mirror system

This work was focused on the model-based design method of two-axis four-actuator(TAFA) fast steering mirror system(FSM), in order to improve the design efficiency. The structure and operation principle commonality of normal TAFA FSM were investigated. Based on the structure and the commonality, the conditions of single-axis idea, high-frequency resonance and coupling were modeled gradually. Combining these models, a holonomic system model was established to reflect and predict the performance of TAFA FSM. A model-based design method was proposed based on the holonomic system model. The design flow and design concept of the method were described. In accordance with the method, a TAFA FSM was designed. Simulations and experiments of the FSM were done, and the results of them were compared. The compared results indicate that the holonomic system model can well reflect and predict the performance of TAFA FSM. The bandwidth of TAFA FSM is more than 250 Hz; adjust time is less than 15 ms;overshoot is less than 8%; position accuracy is better than 10 μrad; the FSM prototype can satisfy the requirements.

Dynamic modeling and nonlinear control strategy for an underactuated quad rotor rotorcraft

In this paper, a nonlinear dynamic MIMO model of a 6-DOF underactuated quad rotor rotorcraft is derived based on Newton-Euler formalism. The derivation comprises determining equations of motion of the quad rotor in three dimensions and seeking to approximate the actuation forces through modeling of the aerodynamic coefficients and electric motor dynamics. The derived model is dynamically unstable, so a sequential nonlinear control strategy is implemented for the quad rotor. The control strategy includes exact feedback linearization technique, using the geometric methods of nonlinear control. The performance of the nonlinear control algorithm is evaluated using simulation and the results show the effectiveness of the proposed control strategy for the quad rotor rotorcraft near quasi-stationary flight.

Linearization of T-S fuzzy systems and robust H_∞ control

Takagi-Sugeno(T-S) fuzzy model is difficult to be linearized because of membership functions included.So,novel T-S fuzzy state transformation and T-S fuzzy feedback are proposed for the linearization of T-S fuzzy system.The novel T-S fuzzy state transformation is the fuzzy combination of local linear transformation which transforms local linear models in the T-S fuzzy model into the local linear controllable canonical models.The fuzzy combination of local linear controllable canonical model gives controllable canonical T-S fuzzy model and then nonlinear feedback is obtained easily.After the linearization of T-S fuzzy model,a robust H∞ controller with the robustness of sliding model control(SMC) is designed.As a result,controlled T-S fuzzy system shows the performance of H∞ control and the robustness of SMC.

Application of Refactoring and Design Pattern in Land Information System Development

The unceasing change problem of land information systems can be resolved through the refactoring and design pattern. To promote the implementation of design pattern and refactoring methods in developing land information systems reusing software design, applying refactoring methods to the abstract factory and decorator design patterns in land information system development is discussed.

A Theory of Secure Mobile Computation with Confined Movement and Communication

An extended π calculus was introduced to deal with secure movement and intercommunication between agents. The system extends Nomadic-π with objective migration primitive and confined region which serves as annotation labels of agents and channels. The confined region labels were used to uniquely identify the constraints on the migration and communication of agents, with the labels, the agents could be confined in a secure subsystem and the inter-agent communication could be confined between agents located on trusted sites during computation. The operational semantics for the calculus was given out, and a type system which enforces security properties called confined migration and confined communication was developed.

Comparative Study of Response Surface Designs with Errors-in-Variables Model

This paper investigates the scaled prediction variances in the errors-in-variables model and compares the performance with those in classic model of response surface designs for three factors.The ordinary least squares estimators of regression coefficients are derived from a second-order response surface model with errors in variables.Three performance criteria are proposed.The first is the difference between the empirical mean of maximum value of scaled prediction variance with errors and the maximum value of scaled prediction variance without errors.The second is the mean squared deviation from the mean of simulated maximum scaled prediction variance with errors.The last performance measure is the mean squared scaled prediction variance change with and without errors.In the simulations,1 000 random samples were performed following three factors with 20 experimental runs for central composite designs and 15 for Box-Behnken design.The independent variables are coded variables in these designs.Comparative results show that for the low level errors in variables,central composite face-centered design is optimal;otherwise,Box-Behnken design has a relatively better performance.

Vehicle kinematics modeling and design of vehicle trajectory generator system

A trajectory generator based on vehicle kinematics model was presented and an integrated navigation simulation system was designed.Considering that the tight relation between vehicle motion and topography,a new trajectory generator for vehicle was proposed for more actual simulation.Firstly,a vehicle kinematics model was built based on conversion of attitude vector in different coordinate systems.Then,the principle of common trajectory generators was analyzed.Besides,combining the vehicle kinematics model with the principle of dead reckoning,a new vehicle trajectory generator was presented,which can provide process parameters of carrier anytime and achieve simulation of typical actions of running vehicle.Moreover,IMU(inertial measurement unit) elements were simulated,including accelerometer and gyroscope.After setting up the simulation conditions,the integrated navigation simulation system was verified by final performance test.The result proves the validity and flexibility of this design.

Multi-loop Internal Model Controller Design Based on a Dynamic PLS Framework

In this paper,a multi-loop internal model control(IMC) scheme in conjunction with feed-forward strategy based on the dynamic partial least squares(DyPLS) framework is proposed.Unlike the traditional methods to decouple multi-input multi-output(MIMO) systems,the DyPLS framework automatically decomposes the MIMO process into a multi-loop system in the PLS subspace in the modeling stage.The dynamic filters with identical structure are used to build the dynamic PLS model,which retains the orthogonality among the latent variables.To address the model mismatch problem,an off-line least squares method is applied to obtain a set of optimal filter parameters in each latent space.Without losing the merits of model-based control,a simple and easy-tuned IMC structure is readily carried over to the dynamic PLS control framework.In addition,by projecting the measurable disturbance into the latent subspace,a multi-loop feed-forward control is yielded to achieve better performance for disturbance rejection.Simulation results of a distillation column are used to further demonstrate this new strategy outperforms conventional control schemes in servo behavior and disturbance rejection.

A role based coordination model in agent systems

Coordination technology addresses the construction of open, flexible systems from active and independent software agents in concurrent and distributed systems. In most open distributed applications, multiple agents need interaction and communication to achieve their overall goal. Coordination technologies for the Internet typically are concerned with enabling interaction among agents and helping them cooperate with each other. At the same time, access control should also be considered to constrain interaction to make it harmless. Access control should be regarded as the security counterpart of coordination. At present, the combination of coordination and access control remains an open problem. Thus, we propose a role Dased coordination model with policy enforcement in agent application systems. In this model, coordination is combined with access control so as to fully characterize the interactions in agent systems. A set of agents interacting with each other for a common global system task constitutes a coordination group. Role based access control is applied in this model to prevent unauthorized accesses. Coordination policy is enforced in a distributed manner so that the model can be applied to the open distributed systems such as Internet. An Internet online auction system is presented as a case study to illustrate the proposed coordination model and finally the performance analysis of the model is introduced.

Performance Analysis of Uplink Distributed Massive MIMO System with Cross-Layer Design over Rayleigh Fading Channel

The performance of uplink distributed massive multiple-input multiple-output(MIMO)systems with crosslayer design(CLD) is investigated over Rayleigh fading channel, which combines the discrete rate adaptive modulation with truncated automatic repeat request. By means of the performance analysis, the closed-form expressions of average packet error rate(APER)and overall average spectral efficiency(ASE)of distributed massive MIMO systems with CLD are derived based on the conditional probability density function of each user’s approximate effective signal-to-noise ratio(SNR)and the switching thresholds under the target packet loss rate(PLR)constraint.With these results,using the approximation of complementary error functions,the approximate APER and overall ASE are also deduced. Simulation results illustrate that the obtained theoretical ASE and APER can match the corresponding simulations well. Besides,the target PLR requirement is satisfied,and the distributed massive MIMO systems offer an obvious performance gain over the co-located massive MIMO systems.

USING SYSTEM SIMULATION METHOD AND CAD TECHNIQUE TO SOLVE THE MINING ENGINEERING RELIABILITY IN SURFACE MINES

Subjected to various stochastic factors, surface mining engineering reliability is difficult to solve by using general reliability mathematical method.The concept of reliability measurement is introduced; And the authors have combined system simulation method with CAD technique and developed an interactive color character graphic design system for evaluating and solving the mining engineering reliability in surface mines under the given constraints.

A prototype of workflow management system for construction design projects

A great deal of benefits can be achieved if information and process are integrated within the building design project. This paper aims to establish a prototype of workflow management system for construction design project through the application of workflow technology. The composition and function of prototype is presented to satisfy the needs of information share and process integration. By integrating all subsystems and modules of the prototype, the whole system can deal with design information-flow modeling, emulating and optimizing, task planning and distributing, automatic tracking and monitoring, as well as network service, etc. In this way, the collaborative design environment of building design proiect is brought into being.

Modular High-Power Electronics for a High-Speed MLC Flywheel Energy Storage System

The operation of a motor drive for high-power, high-speed applications, especially for the permanent-magnet synchronous AC motors with regeneration capability is presented. Power system utilizes a SVHPWM （space-vector-based hybrid pulse width modulation） for a reduced harmonic distortion and switching loss. Associated electromagnetic interference mitigation and cooling requirements are significantly reduced. Voltage source inverter drives a three-phase MLC200 flywheel. The modularity of the proposed topology also simplifies overall system design and manufacturability. The system topology and control strategy are discussed. Simulation results are presented to illustrate the harmonic distortion and switching loss reduction and reduced line current ripple.

Research on an Integrated Modeling Method of Virtual Ship Assembly

A new method of virtual ship assembly modeling which integrates ship three-dimensional design and ship construction planning was described in this paper. A workflow model of simulation modeling based on the virtual ship assembly process was also established; furthermore, a method of information transformation between the ship three-dimensional design and ship construction plan was formulated. To meet the requirements of information sharing between different systems in the ship virtual assembly, a simulation database was created by using the software engineering design method and the relational data model. With the application of this database, the information of ship three-dimensional design, construction planning, and virtual assembly can be integrated into one system. Subsequently, this new method was applied as a tool to simulate the virtual assembly of a ship, and the results guarantee its rationality and reliability.