Research on Cooperative Design Network Security Based on IP-VPN

As the important method and instrument of agile manufacture,the technology of distributed collaborative design and manufacturing has become the hotspot of manufacturing. The basic concept and key technologies of IP_VPN are introduced in this paper,and a collaborative design network model based on IP_VPN is presented. Distributed collaborative design is a multi_user,multitask involved system, which is consisted of lots of collaborative processs,so the network security is the key of distributed collaborative design. We research on the security of collaborative design network based on IP_VPN, hence get a conclusion:we can construct an economical?practical and secure collaborative design network system by the application of data encryption,user authentication and access control based on the role,etc.     

Digital Beamforming for Unified Spread Spectrum TT&C System

In TT&C system,unified spread spectrum framework and adaptive antenna digital beamforming technologies are used to track, telemetry and command objects. Constant modulus array (CMA) and adaptive signal canceller estimate the direction of arrival (DOA) of every signal and use the optimum weighted vector to form the beams. The phase weighted vectors estimated from DOA improve the processing gain as well as being utilized in the transmitting of tele command signal to form the beam of specified object. Its processing performance is researched and simulated in this paper.     

Soft-switching Analysis Phase-Shifted-FB-ZVS-PWM DC-DC Converter With Saturable Inductor

Compared with the traditional full-bridge(FB)zero-voltage-switched(ZVS) pulsewidth-modulated(PWM) converter, the FB-ZVS-PWM converter with a saturable inductor has a wider load range with ZVS and smaller circulating energy as well as smaller duty cycle loss. By analyzing the operation principle of the converter, this paper studies design considerations of the parameter bringing about ZVS and dead time of the switch, and gives out the design method, finally simulation testing has been carried out.     

Harmonic Analysis and Suppression of High-frequency Welding Devices

This paper analyzes the structure and line current waveform of 3-phase AC voltage regulation circuit. As an application of 3-phase AC voltage regulation circuit, a high-frequency welding device's simulation model and harmonic analysis of line current are presented. Results of simulation are compared to field measurements. The two are in a good agreement, so this simulation model is correct. Two single-tuning filters and one second-order HPF are designed according to the device's harmonic condition. Simulation results of the circuit with filters indicate decrease of the harmonics in current of power supply, and the waveform is close to sinusoidal wave, which prove correctness of the solution to harmonics pollution.     

Building Enviornmental Monitoring System With COM

This article presents an implement of component using COM technology for collecting environmental monitoring data in environment monitoring system. The component makes the separation of data collection and data analysis available.Simultaneously by using the interface of connectable object in COM,itmakes the cooperation of the environment monitoring software with other parts of fault management software available,and also the seamless connection.It improves the system's performance by adding extensibility and potential cooperatibility.     

Direct Factor Analysis With Discrete X-Ray Diffraction Patterns

In this paper,we put forward a method of direct factor analysis with discrete X-ray diffraction patterns, which was supported by the experimental measurement with the mixture containing 2,3,4,5 phases respectively. The detailed discussion was also given to its principles,errors and criterion.     

VARIABLE DAMP STRUCTURAL RELIABILITY DUE TO MULTIPLE RANDOM EXCITATIONS AND SENSETIVITY ANALYSIS

The reliability of random vibration is discussed,and then by using the first order perturbation method and with the aid of relation of the systemic response function to the first order sensetivity of variable damp parameter, the rate of change of structural reliability indication is derived, therefore the constraint equation to guarantee reliability for the structural optimization design is proved and the satisfactory result is obtained,test and the practicability of this method is tested.     

Research and Realization of Calculating Artery Compliance Using Oscillometric Method

This paper presents a method that can non-invasively detect artery compliance using oscillometric method.There are also researches about Windkessel theory,and analysis of the combination of Windkessel and oscillometric method.Then the authors summarize a method to calculate artery compliance and introduce the clinical effect in the hospital.Compared with traditional sphygmomanometer,they get the pertinence of SBP is r=0.918 5(P<0.001).And the pertinence of DBP is r=0.899(P<0.001).Then it is compared with ultrasonic method,the pertinence of compliance is r=-0.820 9(P<0.01).This proves that the diagnose of blood pressure and artery compliance is effective and artery compliance is an important index in cardiovascular clinical measurement.So this paper makes the oscillometric method to be applied to wide ranges in calculating cardiovascular indexs.