Markov process based reliability model for laser diodes in space radiation environment

The reliability of laser diodes is a prerequisite for use in satellite optical communication systems, which is significant influenced by both displacement damage effect and annealing effect. A reliability model was proposed to evaluate the reliability and lifetime for laser diodes in space radiation environment. Degradation process is separated into discrete states, and reliability model is subsequently established based on Markov process. The Markov process consists of a Poisson process and an exponential process, representing the displacement damage effect and annealing effect, respectively. Reliability characteristics of a given laser diode are simulated over 100,000 h, and applicability of this reliability model is demonstrated by analyzing the variety trend of probability density of performance states.     

A review of reliability prediction methods for electronic devices

A wide range of reliability prediction methods is available today for electronic systems. This article classifies the commonly used and referred to reliability prediction methodologies into some categories easy to understand. A set of selected methods, which are of relevance to many industries, the aerospace industry among others, are reviewed and the possibility they offer to address the stated objectives is assessed. Their respective advantages and shortcomings are the basis for the recommendation we make to use the methods in a combined fashion (simultaneously or successively) along the product development process.     

Enhanced electronic system reliability - challenges for temperature prediction

Using telecommunication as an example, it is argued that the electronics industry badly needs a change in attitude toward reliability thinking. The role of thermal design and reliability qualification is discussed in context of current industrial needs for short design cycles and rapid implementation of new technologies. Current and future practices are discussed in the context of newly-emerging reliability standards. Finally, two multi-company projects targeting the improvement of reliability through better temperature-related information are described.     

Numerical methods for reliability evaluation of Markov closedfault-tolerant systems

This paper compares three numerical methods for reliability calculation of Markov, closed, fault-tolerant systems which give rise to continuous-time, time-homogeneous, finite-state, acyclic Markov chains. The authors consider a modified version of Jensen's method (a probabilistic method, also known as uniformization or randomization), a new version of ACE (acyclic Markov chain evaluator) algorithm with several enhancements, and a third-order implicit Runge-Kutta method (an ordinary-differential-equation solution method). Modifications to Jensen's method include incorporating stable calculation of Poisson probabilities and steady-state detection of the underlying discrete-time Markov chain. The new version of Jensen's method is not only more efficient but yields more accurate results. Modifications to ACE algorithm are proposed which incorporate scaling and other refinements to make it more stable and accurate. However, the new version no longer yields solution symbolic with respect to time variable. Implicit Runge-Kutta method can exploit the acyclic structure of the Markov chain and therefore becomes more efficient. All three methods are implemented. Several reliability models are numerically solved using these methods and the results are compared on the basis of accuracy and computation cost     

Approximate sensitivity analysis for acyclic Markov reliability models

Acyclic Markov chains are frequently used for reliability analysis of nonmaintained mission-critical computer-based systems. Since traditional sensitivity (or importance) analysis using Markov chains can be computationally expensive, an approximate approach is presented which is easy to compute and which performs quite well in test cases. This approach is presented in terms of a Markov chain which is used for solving a dynamic fault-tree, but the approach applies to any acyclic Markov reliability model.     

A nodes scheduling model based on Markov chain prediction for big streaming data analysis

Streaming data analysis is an important part of big data processing. However, streaming data is difficult to be analyzed and processed in real time because of the rapid data arriving speed and huge size of data set in stream model. The paper proposes a nodes scheduling model based on Markov chain prediction for analyzing big streaming data in real time by following three steps: (i) construct data state transition graph using Markov chain to predict the varying trend of big streaming data; (ii) choose appropriate cloud computing nodes to process big streaming data depending on the predicted result of the data state transition graph; and (iii) assign big streaming data to these computing nodes using the load balancing theory, which ensures that all subtasks are accomplished synchronously. Experiments demonstrate that the proposed scheduling algorithm can fast process big streaming data effectively. Copyright © 2014 John Wiley & Sons, Ltd.     

LSI reliability prediction based on time

The proposed reliability prediction model takes into account the development of integrated circuit technology as well as the general improvement of the reliability with time.The basic factor of the model is the circuit complexity. Besides the complexity the chip size and temperature factors are also included in the model. The model is applicable to both SSI-, MSI- and LSI-devices.     

Modeling and analysis of communication systems based oncomputational methods for Markov chains

The authors describe a computational approach for modeling and analyzing modern communication systems based on numerical methods for Markov chains. Advanced direct and iterative procedures for the calculation of the stationary distribution of a homogeneous discrete- or continuous-time Markov chain with finite state space are presented. They are implemented in a convenient software tool called MACOM for interactive modeling and performance evaluation of communication systems. MACOM provides the user with a predefined markovian model world describing modern telecommunication networks with adaptive routing schemes and advanced congestion-control mechanisms. The versatility of these algorithms is illustrated by their application to Markovian queuing models derived from telecommunications networks     

电子产品在焊接过程中的可靠性探究

随着电子制造业的发展,电子产品在焊接过程中的可靠性问题越来越突出,对电子产品可靠性研究已成为学术界和产业界非常关注的问题。本文主要针对电子产品在焊接过程中的可靠性问题进行相关研究,阐述了可靠性的几大影响因素,并介绍了几种可靠性检测技术。     

Probabilistic behavior and reliability analysis for a multi-robot system by applying Petri net and Markov renewal process theory

The strategic importance of robots in the workplace has greatly increased in recent years as an ever wider variety have been introduced into a whole host of industrial production lines. However, when these robots are examined in the context of the entire production system a number of problems can be identified. Firstly, the slowness of the operating time and secondly the fall-off in efficiency and reliability of the system when a robot is integrated with other units.This paper seeks to carefully analyze the behavior of two robots in a combination of arrangements. The robots operate independently and in coordination with each other and then each of them operates in conjunction with a conveyer incorporated in the system. Operations are then represented in a Petri net model and analysis of probabilistic behavior and reliability is performed with introducing of Markov renewal process.In terms of numerical examples a comparison of uniform and non-uniform mean operating time intervals is made in order to determine the effect of irregularities in robot operations on the system as a whole.     

Thermal monitoring and testing of electronic systems

The paper presents a method for online overheating protection of electronic systems. The key elements of the implementation, the thermal sensor and a chip dedicated to thermal monitoring of the various components are presented in details. Beyond on line thermal monitoring, offline static and transient thermal testing are also enabled by the suggested method, using the standard test circuitry and boundary scan     

Statistical simulations for flash memory reliability analysis and prediction

In this paper, through the use of a recently proposed statistical model of stress-induced leakage current, we will investigate the reliability of actual flash memory technologies and predict future trends. We investigate either program disturbs (namely gate and drain disturbs) and data retention of state-of-the-art flash memory cells and use this model to correlate the induced threshold voltage shift to the typical outputs coming from oxide characterization, that are density, cross section, and energy level of defects. Physical mechanisms inducing the largest threshold voltage (V/sub T/) degradation will be identified and explained. Furthermore, we predict the effects of tunnel oxide scaling on flash memory data retention, giving a rule of thumb to scale the tunnel oxide while maintaining the same retention requirements.     

BP神经网络在元器件非工作可靠性参数预测中的应用

应用神经网络模型对某电子元器件在非工作状态时的可靠性性能参数时间序列进行预测,并与自回归模型预测结果进行了比较.检验结果表明,神经网络预测模型有较高的精度,具有很好的实用价值.     

Effects of design automation on the reliability and maintainability design of electronic systems

The ability to design required reliability and maintain-ability performance into electronic systems has become more difficult due to system complexity. Design automation offers an alternative to traditional approaches of managing the complexity problem. This alternative depends almost exclusively on the computer and is implemented via a set of tightly or loosely integrated programs.     

Performance analysis of opportunistic spectrum access based on partially observable Markov decision process

To maximize the throughout of AD hoc system with opportunistic spectrum access (OSA) among multiple secondary users is analyzed. Two distributed learning and allocation schemes are studied by using greedy and random approach, which can maximize the cognitive system throughput or equivalently minimize the total regret in distributed learning and allocation. The simulation results show that the performance of OSA in AD hoc system are affected by package arrival rate and the number of second users. When the second users are less than six, or the package arrival rate is less than 0.06, the throughput of greedy approach is higher than that of random approach, and greedy approach is recommended to be adopted in the design of OSA in AD hoc system.     

基于累积特性分析的注塑过程质量预测

注塑过程为现代社会提供了大量、丰富、高品质的塑料制品。如何保证我国注塑成型过程的精确、高效运行,生产出高质量的产品,及时可靠的质量预测已成为亟待解决的问题。本文针对注塑过程已有方法的不足,提出了基于累积特性分析的质量预测方法,实际工业实验表明了所提出方法的有效性。     

基于加速寿命试验的SLD可靠性预计模型研究

超辐射发光二极管(SLD)已广泛应用于航空、航天等多个领域,但其预计模型的缺失使得SLD的可靠性分析工作缺乏有效指导。本文基于SLD主要失效模式、失效机理以及典型诱发应力,构建SLD可靠性预计模型,开展加速寿命试验,利用性能退化可靠性评估技术、图估计、最优线性无偏估计等方法对试验数据进行分析处理,确定管芯预计模型参数,应用国内外已有耦合、热阻及制冷器可靠性预计技术,确定管芯耦合及组件预计模型系数的表征,从而完成SLD可靠性预计模型的建立,为SLD工程应用过程中的可靠性分析工作提供技术参考。     

Neural network for the reliability analysis of simplex systems

A new approach to the reliability analysis, based on neural networks, is introduced in this paper. The reliability analysis of a simple nonredundant digital system, Simplex System, with repair is used to illustrate the neural network approach. The discrete-time Markov model of simplex systems is realized using feed-forward recursive neural network. The energy function and update equations for the weights of the neural network are estabilished such that the network converges to the desired reliability of the simplex system under design. The failure rate and repair rate, satisfying the desired reliability, are extracted from the neural weights at convergence. The obtained results are verified by the conventional approach.     

基于AVR的太阳能高速公路智能电子显示屏系统设计

针对LED电子显示屏在高速公路智能交通管理实际应用中存在着的问题,设计了一种基于AVR的太阳能高速公路智能电子显示屏系统。该系统采用单片机ATMEGA8接收超声波检测信号,并控制无线发送模块向AT-MEGA128主控模块发送车辆有无信号,主控模块接收到无线信号后,控制LED点阵显示屏及LCD液晶显示屏实时信息显示。实验结果表明该系统性能稳定、实时性高、节能、环保、具有良好的应用前景。