Reliability investigation of 0.07-/spl mu/m InGaAs-InAlAs-InP HEMT MMICs with pseudomorphic In/sub 0.75/Ga/sub 0.25/As channel

The authors have investigated the reliability performance of G-band (183 GHz) monolithic microwave integrated circuit (MMIC) amplifiers fabricated using 0.07-/spl mu/m T-gate InGaAs-InAlAs-InP HEMTs with pseudomorphic In/sub 0.75/Ga/sub 0.25/As channel on 3-in wafers. Life test was performed at two temperatures (T/sub 1/ = 200 /spl deg/C and T/sub 2/ = 215 /spl deg/C), and the amplifiers were stressed at V/sub ds/ of 1 V and I/sub ds/ of 250 mA/mm in a N/sub 2/ ambient. The activation energy is as high as 1.7 eV, achieving a projected median-time-to-failure (MTTF) /spl ap/ 2 /spl times/ 10/sup 6/ h at a junction temperature of 125 /spl deg/C. MTTF was determined by 2-temperature constant current stress using /spl Delta/G/sub mp/ = -20% as the failure criteria. The difference of reliability performance between 0.07-/spl mu/m InGaAs-InAlAs-InP HEMT MMICs with pseudomorphic In/sub 0.75/Ga/sub 0.25/As channel and 0.1-/spl mu/m InGaAs-InAlAs-InP HEMT MMICs with In/sub 0.6/Ga/sub 0.4/As channel is also discussed. The achieved high-reliability result demonstrates a robust 0.07-/spl mu/m pseudomorphic InGaAs-InAlAs-InP HEMT MMICs production technology for G-band applications.     

Multidimensional augmented current equation including velocityovershoot

The augmented drift-diffusion current equation, which includes velocity overshoot effects through the space derivatives of the electric field, cannot be directly extended beyond one dimension. A new formalism is developed which considers the carrier heating and the distribution relaxation effects to obtain a multidimensional augmented drift diffusion current equation. The equivalent mobility containing the velocity overshoot correction is derived from the perturbation analysis on the carrier temperature using the energy balance equation. The issues related to the numerical implementation of this generalized model and the validity of the assumptions are also discussed     

电厂电气运行中常见故障分析及其应对措施探讨

为了保证电厂的生产效率,必须要分析电气的运行特征,确定电气故障发生的原因,综合考虑多方面因素,选择切实可行的措施解决问题。简要分析了电厂电气运行常见故障发生原因,并提出了相应的解决措施。     

Creating a live, public short message service corpus: the NUS SMS corpus

Short Message Service (SMS) messages are short messages sent from one person to another from their mobile phones. They represent a means of personal communication that is an important communicative artifact in our current digital era. As most existing studies have used private access to SMS corpora, comparative studies using the same raw SMS data have not been possible up to now. We describe our efforts to collect a public SMS corpus to address this problem. We use a battery of methodologies to collect the corpus, paying particular attention to privacy issues to address contributors’ concerns. Our live project collects new SMS message submissions, checks their quality, and adds valid messages. We release the resultant corpus as XML and as SQL dumps, along with monthly corpus statistics. We opportunistically collect as much metadata about the messages and their senders as possible, so as to enable different types of analyses. To date, we have collected more than 71,000 messages, focusing on English and Mandarin Chinese.     

Impacts of employee participation and trust on e-business readiness, benefits, and satisfaction

An increasing number of firms have invested large sums in implementing electronic business (e-business). Nowadays, while the e-businesses are fostering rapid industrial growth, employees are the one who factually engage with information exchange, communication and support e-business processes. However, prior literature has paid scant attention in determining e-business value and its drivers from employee perspective. Thus, the present study attempts to investigate how user participation and trust drives e-business value in terms of e-business readiness, e-business benefits, and e-business satisfaction. For this sake, data collected from 143 employees at Taiwanese IT related firms and analyzed with partial least square (PLS) structural equation approach reveal that trust and user participation were significant precursors of employee e-business satisfaction. The results strongly support the contention that trust directly affects e-business satisfaction, and indirectly affects it through e-business readiness and e-business benefits. The research model and findings will help managers implement e-business successfully and offer valuable references for researchers interested in developing related theories.     

Infrared target tracking based on proximal robust principal component analysis method

Applied Intelligence - Infrared target tracking plays an important role in both civil and military fields. The main challenges in designing a robust and high-precision tracker for infrared...     

基于偏序关系的遗传算法求解多峰函数优化问题

该文设计了基于偏序关系的演化算法求解多峰函数优化问题新算法。并从偏序关系的性质出发,从理论上为该算法的收敛性提供了一定的依据,进而为其搜索操作提供了明确的方向,避免了演化搜索过程中的盲目性。     

模糊核聚类的自适应算法

针对模糊聚类算法在样本特征不明显时不能取得很好的聚类效果，以及现有的模糊聚类算法需要事先确定聚类数，随机性强、容易陷入局部最优等弱点，将核函数和有效性函数引入到模糊聚类中，提出了模糊核聚类的自适应算法,此方法在性能上比经典的聚类算法有了较大的改进,取得了更好的聚类效果,实验结果证实了该方法的有效性和可行性.     

网络服务器软件老化现象的测试与分析

提出了一种测试软件老化过程的实验方案，编制了实现该方案的软件工具集，并以应用广泛的Apache网络服务器为目标，研究了当负载为泊松流时服务器的老化现象，用回归分析和ARIMA(自回归差分滑动平均)模型分析了剩余内存的变化情况。结果表明ARIMA模型可以较好地描述和预测内存的使用情况。