FEATURE SOLID MODELING TOOL SYSTEM:FSMTS

In conformity with the principle of Design for Manufacture,feature-based design strate-(?)es have been developed.As the“feature”is relevant to the“macro process plan”and“macro NCprograms”,obviously,“feature”is beyond the power of conventional solid modellers.Neverthe-less,substantial breakthrough has not been made in the solid modeling field,except“feature at-taching”or“feature recognizing”methods have been taken on.In this paper,the theory,concepts,system architecture,and algorithm principles of solid modeling tool system have beenrepresented.The practice of Feature Solid Modeling Tool System (FSMTS) developed atHuazhong University has proved that the tool may be a new foundation of Feature-Based Design.     

Identification of delayed system using instrumental variable method

System identification uses system inputs and outputs to raise mathematical models.Various techniques of system identification exist that offer a nominal model and an uncertainty bound.Many practical systems such as thermal processes & chemical processes have inbuilt time delay.If the time delay used in the system model for controller design does not concur with the actual process time delay,a closed-loop system may be unstable or demonstrate unacceptable transient response characteristics so here the time delay is assumed to be time-invariant. This paper proposes on-line identification of delayed complex/uncertain systems using instrumental variable(Ⅳ) method.Parametric uncertainty has been considered which may be represented by variations of certain system parameters over some possible range.This method allows consistent estimation when the system parameters are associated with the noise terms,as the IV methods(IVM’s)usually make no assumption on the noise correlation configuration.The faster convergence of the parameters including noise terms has been proved in this paper.Iterative prefiltering(IP)method has also been used for the identification of the delayed uncertain system and the graphical results given in this paper demonstrate that the convergence results are inferior to the instrumental variable method.     

The NC system based on positioning controller for Spin Riveting Machine

This article discusses in details the NC system based on positioning controller, PLC and graphic operation terminal of Mitsttbishi. It has been used successfully in the spin riveting machine we developed.     

Functional-Level Fault Simulation with Concurrent and Parallel Mechanisms Using Object-Oriented VLSI Model

The functional-level test has been proposed as an alternative to reduc the complexity of test when VLSI gets larger and more complicated.It has been successful for circuits such as memories,PLAs and microprocessors.However,the functional-level test for general functional models has sedldom been studied.This paper presents an object-oriented VLSI model and a functional-level fault simulation methodology for general functional model.Based on the proposed VLSI model,FFS(Functional-level Fault Simulator)with friendly visual interface has been implemented on Microsoft Windows platform by use of C .It is an integral part of MVS(Functional test Modeling and Verification System)--an extended subsystem of TeDS(Test Development System).The goal of FFS is to determine the fault coverage,generate fault dictionary and compact original test set at the function-level.In order to be efficient,FFS uses the concurrent and parallel mechanisms by taking advantage of the object-oriented VLSI model.The object-oriented VLSI model based fault simulation has been validated in the functional-level test by simulation results and the satisfying performance of FFS.     

构建数字城市的元数据服务体系

Metadata is one of the six key technologies of Digital Earth,which is also an important aspect in buildingand implementing the Digital City. Based on the technologies and standards of Web Services ,the author came up witha metadata services architecture in the distributed heterogeneous network environment of Digital City. In this paper,the metadata services architecture is described and explained in detail,including the related standards,technologies,and the practical experiences in the ‘Metadata Sharing Network Project of Digital Beijing‘ as well. It also points out that, based on the Web service ,to build the metadata service architecture will be practically meaningful for organizing,managing and sharing the information resources in Digital City.     

竞争监督学习法在集成型识别系统中的应用1)

In pattern recognition application,integration of artificial neural networks has been recognized as a powerful tool,but the performance of the sub-classifiers has effect on the performance of the whole integration system.In this paper,we apply the proposed algorithm——Competitive Supervised Learning Algorithm to the integrated recognition neural network system. Experimental results have confirmed that the proposed algorithm improves lear-ning and generalization of the system.     

Performance gain with variable chunk size in GFS-like file systems

We have designed and implemented Tianwang File System（TFS）, which is a distributed file system much like Google File System（GFS）. The system has its origins in our Tianwang search engine and web mining research work. Our system has the same assumptions and the same architectures with GFS. But the key design choice that the chunk size is variable lets our system to adopt simpler system interactions which significantly improves the performance of the record append operation. In this paper, we discuss many aspects of our design which are different from GFS, and verify their pros and cons by performance experiments. The experiment results shows that the utilization ratio of our record append operation excels GFS by 25%. And the throughput of record append of TFS is also several times better.     

Nonlinear backstepping ship course controller

A ship, as an object of course control, is characterized by a nonlinear function describing the static maneuvering characteristics. The backstepping method is one of the methods that can be used during the designing process of a nonlinear course controller for ships. The method has been used for the purpose of designing two configurations of nonlinear controllers, which were then used to control the ship course. One of the configurations took dynamic characteristic of a steering gear into account during the designing stage. The parameters of the obtained nonlinear control structures have been tuned to optimise the operation of the control system. The optimisation process has been performed by means of genetic algorithms. The quality of operation of the designed control algorithms has been checked in simulation tests performed on the mathematical model of a tanker. The results of simulation experiments have been compared with the performance of the system containing a conventional proportional-derivative （PD） controller.     

Stability and weighted sensitivity analysis of robust controller for heat exchanger

This study presents a parametric system identification approach to estimate the dynamics of a chemical plant from experimental data and develops a robust PID controller for the plant. Parametric system identification of the heat exchanger system has been carried out using experimental data and prediction error method. The estimated model of the heat exchanger system is a time-delay model and a robust PID controller for the time-delayed model has been designed considering weighted sensitivity criteria. The mathematical background of parametric system identification, stability analysis, and ${{\rm H}_\infty }$ weighted sensitivity analysis have been provided in this paper. A graphical plot has been provided to determine the stability region in the $( {{K_{\rm p}},{K_{\rm i}}} )$, $( {{K_{\rm p}},{K_{\rm d}}} )$ and $( {{K_{\rm i}},{K_{\rm d}}} )$ plane. The stability region is a locus dependent on parameters of the controller and frequency, in the parameter plane.     

REMOTE SENSING ANALYSIS OF WASTELAND EXPLOITATICN OF SANJIANG PLAIN IN CHINA

1. Introduction Sanjiang Plain is situated in northeast part of Heilongjiang Province in China. The area is 108,900km~2. The mountain and hill make up 39% and the plain makes up 61% in the whole plain area. The marshland is a special landscape of the plain. After the People's Republic founding, the wasteland has been reclaimed 27,440,000ha. through three times of large scale reclaimation. The farmland has been enlarged three times in 35 years, in which the exploitation speed of state farm system is much faster than county system. Its farmland has been increased from original 7,267ha. to current 1,644,700ha.. The farmland increasing brings about raising of grain production to a great extent.     

数字货币交易匿名性与监管的博弈分析

By using technologies such as blockchain, digital currency, as a new type of monetary asset, has been promoting the development of digital economy. Digital currency trading platform plays an important role in the use of private digital currency by digital currency users. Existing digital currency trading platforms may expose users’ privacy and provide illegal elements with the conditions to participate in various abnormal trading behaviors such as “air dropping” events, extortion, fraud, etc. The strong anonymity protection of users by digital currency trading platforms also make it more difficult for regulatory authorities to supervise digital currency transactions. Therefore, the strength of the anonymity protection of users by digital currency trading platforms need to consider not only the privacy protection of users, but also meet the regulatory requirements. For this reason, based on the analysis of the relationship between the digital currency trading platforms and the supervisory departments, an evolutionary game model was established, the digital currency trading platform and the supervisory game model were defined and con-structed, and the replication dynamic equation was solved and the balanced solution was obtained according to the income matrix between the digital currency trading platform and the supervisory department. By building a Jacobian matrix, the stability of the evolutionary system under different parameters was analyzed. Besides, the evolutionary stable selection and strategy of the digital currency trading platform and the regulatory authority under different conditions were also analyzed. With Matlab, different strategies of anonymity protection of the digital currency trading platform and different strategies of supervision strategy of the regulatory department were simulated to veri-fy the accuracy of the game model. Based on the results of the simulations, some suggestions on the supervision of digital currency trading platforms are put forward, which provides a theoretical basis for the future supervision of digital currency trading platforms in China. © 2022, Beijing Xintong Media Co., Ltd.. All rights reserved.     

Modeling Distributed Multimedia Synchronization with DSPN

Multimedia synchronization is the essential technology for the integration of multimedia in distributed multimedia systems.The multimedia synchronization model has been recognized by many researchers as a premise of the implementation of multimedia synchronization.In distributed multimedia systems,the characteristic of multimedia synchronization is dynamic,and the key medium has the priority in multimedia synchronization.The previously proposed multimedia synchronization models cannot meet these requirements.So a new multimedia dynamic synchronization model-DSPN,based on the timed Petri-net has been designed in this paper.This model can not only let the distributed multimedia system keep multimedia synchronization in a more precise and effective manner according to the runtime situation of the system,but also allow the user to interact with the presentation of multimedia.     

Usability Issues of Grid System Software

This paper addresses the problem why grid technology has not spread as fast as the Web technology of the 1990＇s. In the past 10 years, considerable efforts have been put into grid computing. Much progress has been made and more importantly, fundamental challenges and essential issues of this field are emerging. This paper focuses on the area of grid system software research, and argues that usability of grid system software must be enhanced. It identifies four usability issues, drawing from international grid research experiences. It also presents advances by the Vega Grid team in addressing these challenges.     

A Distributed Model of WebGIS Based on Java Servlett

According to the application of Java in Web Geographical Information System （WebGIS）, a model of WebGIS based on Java Servlet is defined and a new distributed model is proposed. The dislributed model relies on the implementation of distribt, tcd Servlet. And in the model a locator is adopted to manage client access to the Servlet and balance the loads of cluster Web servers. The programming rule of distributcd Servlet and the operating principle of locator are studied in detail. The model has been applied in a practical system, and the actual operating effect shows that it remarkably improves access performance of the WebGIS application and possesses characteristics of load balance, fail-over and so on.     

Power System Stability Improvement by Using STATCOM with POC ＆ Excitation Controller

This paper presents the model of a static synchronous condenser （STATCOM） which is controlled externally by a newly designed power oscillation controller （POC） for the improvements of power system stability and damping effect of an on line power system. The proposed POC consists of two controllers （power oscillation damping ＆ proportional integral derivative PID ＆ POD）. PID parameters have been optimized by Zigler Necles close loop tuning method. Machine excitation has been controller by using excitation controller as required. Both single phase and three phase faults has been considered in the research. In this paper, a power system network is considered which is simulated in the phasor simulation method ＆ the network is simulated in three steps： without STATCOM, with STATCOM but no externally controlled, STATCOM with POC. Simulation result shows that without STATCOM, the system parameters become unstable during faults. When STATCOM is imposed in the network, then system parameters become stable. Again, when STATCOM is controlled externally by POC controllers, then system voltage ＆ power becomes stable in faster way then without controller It has been observed that the STATCOM ratings are only 20 MVA with controllers and 200 MVA without controllers. Therefore, STATCOM with POC controllers are more effective to enhance the voltage stability and increases power transmission capacity of a power system. So STATCOM with POC ＆ excitation controllers, the system performance is greatly enhanced.     

CAD System Dedicated to the Design of Sport Bike Frame Structure

This article aims to discuss the design process of the CAD system dedicated for sport bike frame structure, introducing in detail its design concept and the scheme of implementation. Based on the different usages of sport bikes and the requirements on the system made out by Beijing Hanglun Sport Apparatus Company Limited. Structural analysis on two types of bikes frames is carried out. The system defines the basic design parameters and analyses the constraint conditions.Then calculating formulas with constraint conditions are derived. The system solves equations with Visual C++ program, realizes input of the original data and output of the results through interactive system. With AutoCAD14.0 as the platform, the system uses VC++ and ObjectARX to realize auto output of bike frame graphics. The system has been put into use. Practice has affirmed that the system抯 convenience, applicability and reliability all have reached the expected goal.     

The multiplicity of zeros of algebraic system in eigenvalue method

This article deals with the structure relations between solutions to algebraic system and matrices in eigenvalue method for solving the algebraic system. The authors first discuss the condition on the ideal generated by the given system under which the egienspace of matrix has dimension 1 since in this case the zero can be easily found.Then they study the relations between the multiplicity of zeros of the given system and orders of Jordan blocks of matrices formed in eigenvalue method.     

基于无线传感网络的停车场管理系统

This paper introduces a parking management system based on a wireless sensor network developed by our group. The system consists of a large amount of parking space monitoring nodes, a few parking guiding nodes, a sink node and a management station. All the nodes exchange information with each other through wireless communication. The prototype of the parking management system has been implemented and the preliminary test results show that the performance of the system can satisfy the requirements of the application.     

Modeling of Naval Vessels Combat System based on Complex Network

Naval Vessels Combat System is a kind of complex system.The modeling of combat system has become hot issues in the past years.This paper proposed a new method to establish models of combat system based on the theory of Complex Network.The method of modeling considered the operational entities as nodes.It considered flow of information,substance and energy as edges in a network.The research also carries on a simulation to prove the applicability.Ultimately,the paper concluded that this method is applicable and accurate.