微小卫星单粒子闩锁防护技术研究

对于在轨微小卫星而言,单粒子闩锁(Single Event Latchup,SEL)是最具破坏性的单粒子效应之一,其后果轻则损坏器件,重则使在轨卫星失效。首先介绍了SEL发生机理,分析并总结现有抗SEL的关键技术。其次提出了空间单粒子闩锁防护措施并设计了一种可恢复式抗SEL电源接口电路,实现对卫星星上设备的防闩锁及过流保护。最后利用脉冲激光模拟单粒子效应技术对具有飞行经验的芯片进行实验测试。实验结果表明,该电路能够准确地检测SEL的发生,有效解除SEL效应,保证系统运行稳定可靠。     

Java复合数据类型组件及其MVC模型在GUI定制开发中的应用

针对Java应用程序中GUI的开发,分析MVC架构模式工作原理,阐述Java复合数据类型组件模型-视图-控制器的功能、相互关系及基于MVC模式的设计方法,并进一步详述Swing复合数据类型组件的代理事件与渲染重绘机制.将MVC架构与Swing组件的设计思想融汇在一起,最终揭示了JTable等复合数据类型组件在GUI设计中的灵活应用.     

Java的事件处理机制剖析

Java是面向对象、采用事件驱动机制的程序设计语言,掌握Java的事件处理机制是编写人机交互的图形用户界面程序的关键,论文对Java的事件处理机制进行了深入剖析,阐述了Java的事件处理模式,创建事件监听器对象的四种方法,并以JButton产生的ActionEvent事件的处理为例进行了编程说明。     

基于PLC的SOE虚拟仪器系统的设计与实现

以ＭｏｄｉｃｏｎＴＳＸＱｕａｎｔｕｍＰＬＣ为例,介绍了用户自定义梯形图为功能块的生成方法,叙述了以ＰＬＣ为核的ＳＯＥ虚拟仪器系统的设计与软件实现。     

Application of stochastic discrete event system framework for detection of induced low rate TCP attack

TCP is the most widely accepted transport layer protocol. The major emphasis during the development of TCP was its functionality and efficiency. However, not much consideration was given on studying the possibility of attackers exploiting the protocol, which has lead to several attacks on TCP. This paper deals with the induced low rate TCP attack. Since the attack is relatively new, only a few schemes have been proposed to mitigate it. However, the main issues with these schemes are scalability, change in TCP header, lack of formal frameworks, etc. In this paper, we have adapted the stochastic DES framework for detecting the attack, which addresses most of these issues. We have successfully deployed and tested the proposed DES based IDS on a test bed.     

Event triggered state estimation techniques for power systems with integrated variable energy resources

For many decades, state estimation (SE) has been a critical technology for energy management systems utilized by power system operators. Over time, it has become a mature technology that provides an accurate representation of system state under fairly stable and well understood system operation. The integration of variable energy resources (VERs) such as wind and solar generation, however, introduces new fast frequency dynamics and uncertainties into the system. Furthermore, such renewable energy is often integrated into the distribution system thus requiring real-time monitoring all the way to the periphery of the power grid topology and not just the (central) transmission system. The conventional solution is two fold: solve the SE problem (1) at a faster rate in accordance with the newly added VER dynamics and (2) for the entire power grid topology including the transmission and distribution systems. Such an approach results in exponentially growing problem sets which need to be solver at faster rates. This work seeks to address these two simultaneous requirements and builds upon two recent SE methods which incorporate event-triggering such that the state estimator is only called in the case of considerable novelty in the evolution of the system state. The first method incorporates only event-triggering while the second adds the concept of tracking. Both SE methods are demonstrated on the standard IEEE 14-bus system and the results are observed for a specific bus for two difference scenarios: (1) a spike in the wind power injection and (2) ramp events with higher variability. Relative to traditional state estimation, the numerical case studies showed that the proposed methods can result in computational time reductions of 90%. These results were supported by a theoretical discussion of the computational complexity of three SE techniques. The work concludes that the proposed SE techniques demonstrate practical improvements to the computational complexity of classical state estimation. In such a way, state estimation can continue to support the necessary control actions to mitigate the imbalances resulting from the uncertainties in renewables.     

基于GOOSE的远方备自投在地区110kV电网的应用

远方光纤备自投装置具有通信功能,可以与其他变电站的远方备用电源自动投入装置交换信息,更能够根据多个变电站之间联络线路及电源进出线路的信息,实现多个变电站之间的备自投。结合实际工作中遇到的具体情况,对远方光纤备自投作了较全面的分析和详细说明。     

Events Defined by Duration and Severity,With an Application to Network Reliability

Communications networks are highly reliable and almost never experience widespread failures. But from time to time performance degrades and the probability that a call is blocked or fails to reach its destination jumps from nearly 0 to an unacceptable level. High but variable blocking may then persist for a noticeable period of time. Extended periods of high blocking, or events, can be caused by congestion in response to natural disasters, fiber cuts, equipment failures, and software errors, for example. Because the consequences of an event depend on the level of blocking and its persistence, lists of events at specified blocking and duration thresholds, such as 50% for 30 minutes or 90% for 15 minutes, are often maintained. Reliability parameters at specified blocking and duration thresholds, such as the mean number of events per year and mean time spent in events, are estimated from the lists of reported events and used to compare network service providers, transmission facilities, or brands of equipment, for example. This article shows how data obtained with two-stage sampling can be used to estimate blocking probabilities as a function of time. The estimated blocking probabilities are then used to detect and characterize events and to estimate reliability parameters at specified blocking and duration thresholds. Our estimators are model-free, except for one step in a sampling bias correction, and practical even if there are hundreds of millions of observations. Pointwise confidence intervals for reliability parameters as a function of blocking and duration thresholds are built using a kind of “partial bootstrapping” that is suitable for very large sets of data. The performance of the algorithm for event detection and the estimators of reliability parameters are explored with simulated data. An application to comparison of two network service providers is given in this article, and possible adaptations for other monitoring problems are sketched.     

Safety Aspects of Long-term Dry Interim Storage Of Type-b Spent Fuel and Hlw Transport Casks

Abstract

Based on the German decision to minimise transport of spent fuel casks between nuclear power plants, reprocessing plants and central storage facilities several on-site storage facilities were licensed until the end of 2003. Because of the large amount of Type B(U) transport casks which are going to be used for long-term interim storage the question of timelimited Type B(U) licence maintenance during the storage period of up to 40 years has been discussed under different aspects. This paper describes present technical aspects of the discussion. A main aspect of qualification of transport casks for interim storage is the long-term behaviour of the metallic seal–lid system. Here results are presented from current long-term experimental tests with metallic 'Helicoflex' seals in which pool water is enclosed. This series of tests has been performed by the Federal Institute for Materials Research and Testing (BAM) on behalf of the Federal Office for Radiation Protection (BfS) since 2001. Finally, the paper presents a German concept for an exchange of experience, know-how and state-of-the-art between authorities and technical experts with regard to cask dispatch in nuclear facilities. BAM has taken over a central role in this so-called 'coordinating institution for cask dispatching information' ('KOBAF') which entails management of an online database of cask-specific documents and a technical working group meeting twice a year. The goal is to keep comparable technical standards for all nuclear sites and storage facilities which are going to load and dispatch casks of the same or similar types under the responsibility of different German state governments for the coming decades.     

诱发单粒子效应的空间辐射环境

介绍了诱发电子器件和集成电路发生单粒子效应的主要空间辐射环境。讨论了诱发单粒子效应的空间辐射环境类型和区域分布特点,利用SPACE RADIATION软件包、CREME96和OMERE软件包,针对一些典型卫星轨道,给出了计算结果,分析了相关辐射环境的特点和空间分布特征。．