在役过程控制系统的可信性评估技术研究

在役过程控制系统的风险评估、可靠性评估、可用性评估与安全性评估都是系统可信性评估的一个方面,应按照国际标准的要求,采用与国际接轨的方法进行。

基于软件质量模型构建软件可信性评估系统

文章基于软件质量模型的研究成果,分别从认知软件可信性的角度、量化可信性指标的角度以及如何评估软件可信性的角度对软件可信性进行阐述.为了对软件可信性实现量化评估,提出由指标模型层、评估过程和信息层3部分组成的软件可信性评估系统.

可信性管理的最新进展

本文综述了可信性管理的最新进展。作者就可信性管理标准体系、IEC可信性管理系列标准与ISO9000系列标准的关系以及可靠性技术发展情况作了介绍，并对建立计算机辅助可信性管理系统问题进行了探讨。

机电控制系统故障诊断的回顾与展望

回顾状态监测与故障诊断的发展历史;归纳和总结目前故障诊断的主要理论和方法及其存在的问题和解决途径;阐明现代故障诊断的主要内容及发展趋势。

机电控制系统故障诊断

回顾状态监测与故障诊断的发展历史;总结目前故障诊断的主要理论和方法;阐明现代故障诊断的主要内容及发展趋势。

IA64固件层处理器故障注入技术

针对IA64安腾家族处理器,提出了一种固件实现的处理器故障注入技术,克服传统软硬件故障注入方法难以访问复杂处理器内部结构的缺点,并具有开发代价低、对目标系统硬件没有损害、可移植性好等优点.详细阐述了该故障注入技术的原理、故障类型、故障注入工具的结构和实现方法,并通过实验验证了故障注入工具在系统可靠性评测方面的有效性.

An indoor positioning system for mobile target tracking based on VLC and IMU fusion

An indoor positioning system( IPS) is designed to realize positioning and tracking of mobile targets,by taking advantages of both the visible light communication( VLC) and inertial measurement unit( IMU). The platform of the IPS is designed,which consists of the light-emitting diode( LED)based transmitter,the receiver and the positioning server. To reduce the impact caused by measurement errors,both inertial sensing data and the received signal strength( RSS) from the VLC are calibrated. Then,a practical propagation model is established to obtain the distance between the transmitter and the receiver from the RSS measurements. Furthermore,a hybrid positioning algorithm is proposed by using the adaptive Kalman filter( AKF) and the weighted least squares( WLS)trilateration to estimate the positions of the mobile targets.Experimental results show that the developed IPS using the proposed hybrid positioning algorithm can extend the localization area of VLC,mitigate the IMU drifts and improve the positioning accuracy of mobile targets.

Survey on Key Technology Development and Application in Trusted Computing

Trusted computing,which can effectively increase the credibility of information system,has made great achievements and is in continuous development. For country who is going to strengthen network construction like China,it is an important fundamental supporting technology worth researching. China is in the international forefront in the field of trusted computing. This paper gives comprehensive introductions to the new development and application of key technologies in trusted computing,such as various trusted platform modules(TPM、TCM、TPCM),TCG Software Stack(TSS),trusted cloud server and Trusted Execution Environment(TEE). We illustrate the progressing and application extension of these technologies and also point out some key problems worth studying in the future.

A new measure for evaluating spatially related properties of traffic information credibility

With the wide applications of sensor network technology in traffic information acquisition systems,a new measure will be quite necessary to evaluate spatially related properties of traffic information credibility.The heterogeneity of spatial distribution of information credibility from sensor networks is analyzed and a new measure,information credibility function(ICF),is proposed to describe this heterogeneity.Three possible functional forms of sensor ICF and their corresponding expressions are presented.Then,two feasible operations of spatial superposition of sensor ICFs are discussed.Finally,a numerical example is introduced to show the calibration method of sensor ICF and obtain the spatially related properties of expressway in Beijing.The results show that the sensor ICF of expressway in Beijing possesses a negative exponent property.The traffic information is more abundant at or near the locations of sensor,while with the distance away from the sensor increasing,the traffic information credibility will be declined by an exponential trend.The new measure provides theoretical bases for the optimal locations of traffic sensor networks and the mechanism research of spatial distribution of traffic information credibility.

A dual working mode mobile robot system based on visual guiding and visual servoing

A dual operational modes mobile robot system based on visual guiding and visual servo control is presented. This system consists of a mobile robot with a two-axis manipulator and a tele-operation station. In the visual guiding mode, for the robot works in an open loop visual servo control mode, the manipulating burden of the operator is reduced largely. In the visual servo mode the robot can locate the position of the target assigned by the operator and pick it up by its manipulator. With the help of the operator, the diffieuh problems of finding and handling a target in a complicated environment by the robot can be solved easily.

Integrating unascertained measurement and information entropy theory to assess blastability of rock mass

Due to the complex features of rock mass blastability assessment systems, an evaluation model of rock mass blastability was established on the basis of the unascertained measurement （UM） theory and the actual characteristics of the project. Considering a comprehensive range of intact rock properties and discontinuous structures of rock mass, twelve main factors influencing the evaluation blastability of rock mass were taken into account in the UM model, and the blastability evaluation index system of rock mass was constructed. The unascertained evaluation indices corresponding to the selected factors for the actual situation were solved both qualitatively and quantitatively. Then, the UM function of each evaluation index was obtained based on the initial data for the analysis of the blastability of six rock mass at a highway improvement cutting site in North Wales. The index weights of the factors were calculated by entropy theory, and credible degree identification （CDI） criteria were established according to the UM theory. The results of rock mass blastability evaluation were obtained by the CDI criteria. The results show that the UM model assessment results agree well with the actual records, and are consistent with those of the fuzzy sets evaluation method. Meanwhile, the unascertained superiority degree of rock mass blastability of samples S1-$6 which can be calculated by scoring criteria are 3.428 5, 3.453 3, 4.058 7, 3.675 9, 3.516 7 and 3.289 7, respectively. Furthermore, the proposed method can take into account large amount of uncertain information in blastability evaluation, which can provide an effective, credible and feasible way for estimating the blastability of rock mass. Engineering practices show that it can complete the blastability assessment systematically and scientifically without any assumption by the proposed model, which can be applied to practical engineering.

A New Approach to Improve the Reliability of DPDC SCADA Communication Systems

Supervisory Control and Data Acquisition （SCADA） is used broadly to portray control and management solutions in a wide range of industries. SCADA system failure may lead to disastrous consequences since the health and the safety of the public as the economic viability of the community it serves depends on it. After its introduction in DPDC over a decade ago, the SCADA system hardly had any performance upgradation. Currently, the microwave link in SCADA Communication is observing problems that are rendering the entire structure obsolete. This paper revises the possibility to implement a new communication technology and proposes Free Space Optical （FSO） communication to enhance SCADA system reliability. FSO refers to the transmission of modulated visible or infrared （IR） beams through the air to obtain optical communication. Like optical fiber, FSO also uses lasers to transmit data, but instead of enclosing the data stream in a glass fiber, the data is transmitted through the air. It is a secure, cost-effective alternative to other wireless connectivity options.

Research and Design on Remote Meter Reading System based on PLC Technology

With the deepened transformation of China＇s power system, the stability and reliability of power utilization have been dramatically improved, but meter reading data acquisition does not keep pace with the times. With the continuous maturity of low-voltage power line communication （PLC）, this leads us to see hopes of using PLC technology to realize remote meter reading. In this paper, based on current PLC technology and combining domestic and foreign successful cases, a beneficial exploration and research is conducted from the composition and establishment of software and the design of software and protocol.

Factors Influencing the Success of Agricultural Information System （AIS）： A Factor Analysis

This study aims at investigating the AIS （Agricultural Information System） in Hamedan province, Iran, benefiting from the list of criteria for well functioning AISs that were identified in earlier researches. For this purpose, a survey method with multi-stage stratified random sampling technique was used to select 31 agricultural researchers, and 62 extension workers in the province. The data were acquired by questionnaire and structured interviews. The instrument for data collection was subjected to pre-testing, validation and reliability tests. The results of the factor analysis revealed that the criteria could be categorized into four overarching groups based on their inter-correlation. The analysis of mentioned criteria in Hamedan province AIS showed less efficiency and effectiveness than studies conducted in other areas. But among these, two desirable criteria existed. It is recommended that the ecological knowledge system （EKS） should be integrated with AIS, and some ecological and sustainable development criteria should be added to the existing ones.

WELL-POSEDNESS OF THE MODEL DESCRIBING A REPAIRABLE,STANDBY,HUMAN & MACHINE SYSTEM

By using the strong continuous semigroup theory of linear operators we prove the existence of a unique positive time-dependent solution of the model describing a re-pairable, standby, human & machine system.

Information theory in nonlinear error growth dynamics and its application to predictability:Taking the Lorenz system as an example

In nonlinear error growth dynamics,the initial error cannot be accurately determined,and the forecast error,which is also uncertain,can be considered to be a random variable.Entropy in information theory is a natural measure of the uncertainty of a random variable associated with a probability distribution.This paper effectively combines statistical information theory and nonlinear error growth dynamics,and introduces some fundamental concepts of entropy in information theory for nonlinear error growth dynamics.Entropy based on nonlinear error can be divided into time entropy and space entropy,which are used to estimate the predictabilities of the whole dynamical system and each of its variables.This is not only applicable for investigating the dependence between any two variables of a multivariable system,but also for measuring the influence of each variable on the predictability of the whole system.Taking the Lorenz system as an example,the entropy of nonlinear error is applied to estimate predictability.The time and space entropies are used to investigate the spatial distribution of predictability of the whole Lorenz system.The results show that when moving around two chaotic attractors or near the edge of system space,a Lorenz system with lower sensitivity to the initial field behaves with higher predictability and a longer predictability limit.The example analysis of predictability of the Lorenz system demonstrates that the predictability estimated by the entropy of nonlinear error is feasible and effective,especially for estimation of predictability of the whole system.This provides a theoretical foundation for further work in estimating real atmospheric multivariable joint predictability.

Estimation of atmospheric predictability for multivariable system using information theory in nonlinear error growth dynamics

To estimate atmospheric predictability for multivariable system, based on information theory in nonlinear error growth dynamics, a quantitative method is introduced in this paper using multivariable joint predictability limit(MJPL) and corresponding single variable predictability limit(SVPL). The predictability limit, obtained from the evolutions of nonlinear error entropy and climatological state entropy, is not only used to measure the predictability of dynamical system with the constant climatological state entropy, but also appropriate to the case of climatological state entropy changed with time. With the help of daily NCEP-NCAR reanalysis data, by using a method of local dynamical analog, the nonlinear error entropy, climatological state entropy, and predictability limit are obtained, and the SVPLs and MJPL of the winter 500-hPa temperature field, zonal wind field and meridional wind field are also investigated. The results show that atmospheric predictability is well associated with the analytical variable. For single variable predictability, there exists a big difference for the three variables, with the higher predictability found for the temperature field and zonal wind field and the lower predictability for the meridional wind field. As seen from their spatial distributions, the SVPLs of the three variables appear to have a property of zonal distribution, especially for the meridional wind field, which has three zonal belts with low predictability and four zonal belts with high predictability. For multivariable joint predictability, the MJPL of multivariable system with the three variables is not a simple mean or linear combination of its SVPLs. It presents an obvious regional difference characteristic. Different regions have different results. In some regions, the MJPL is among its SVPLs. However, in other regions, the MJPL is less than its all SVPLs.

Assessment on System Reliability of Cable-stayed Bridges Based on Unascertained Measures

To overcome the shortcomings that there are few feasible methods and models in the comprehensive assessment on the system reliability of cable-stayed bridges, a mathematical tool-the unascertalned measure was introduced. First, the basic knowledge of the Unascertained Sets was introduced briefly. Second, the unascertained measure was defined and the comprehensive assessment model was set up. Then the method was introduced to the assessment of the system reliability of a cable-stayed bridge located in Tianjin City. Engineering practices shows that the method can complete the assessment systematically and scientifically without any assumption. The work has significance in theory and practice for the comprehensive assessment of bridge engineering.