Dependence of the stability of organic light-emitting diodes on driving mode

We investigated the effects of pulsed current (PC) and direct current (DC) driving modes on the stability of organic light-emitting diodes with and without hole-injection layers (HILs).Two different HIL materials were used:copper phthalocyanine (CuPc) and 4,4’,4″-tris(3-methylphenylphenylamino)triphenylamine (m-MDTATA).It was found that the half-lives of devices using PC driving modes were different from those of comparable devices using DC driving modes.For the devices without HILs,with CuPc HILs and with MTDATA HILs,the half-lives of the devices were changed by factors of 1.91,1.41 and 0.86,respectively,when operated in PC rather than DC driving modes.Our analysis of the electrical characteristics of the corresponding hole-only devices showed that the number of holes injected into devices was greatly reduced by inserting an m-MTDATA layer compared with other designs.The results indicate that different ratios of injected electrons and holes can be obtained in these devices.Moreover,these ratios play a dominant role in the dependence of the stability of the device on the driving mode.     

山区高速公路隧道进出口偏压的处治对策

新建的山区高速公路，在复杂的地质和地形地貌条件下，隧道进出口往往处于浅埋偏压地段，由此造成了一系列的工程问题，已引起隧道工程人员的广泛重视。针对不同的地形、地质条件分析了洞口偏压的成因，并提出了相应的处治措施，可为隧道施工提供参考。     

A 5.4mW and 6.1％ efficiency fixed-tuned 214GHz frequency doubler with Schottky barrier diodes

A Y-band frequency doubler is analyzed and designed with GaAs planar Schottky diode,which is flip-chip solded into a 50|xm thick quartz substrate.Diode embedding impedance is found by fullwave analysis with lumped port to model the nonlinear junction for impedance matching without the need of diode equivalent circuit model.All the matching circuit is designed "on-chip" and the multiplier is self-biasing.To the doubler,a conversion efficiency of 6.1%and output power of 5.4mW are measured at 214 GHz with input power of 88 mW,and the typical measured efficiency is 4.5%in200~225GHz.     

Fault detection based on H∞ states observer for networked control systems

The influence of random short time-delay to networked control systems (NCS) is changed into an unknown bounded uncertain part. Without changing the structure of the system, an H∞ states observer is designed for NCS with short time-delay. Based on the designed states observer, a robust fault detection approach is proposed for NCS. In addition, an optimization method for the selection of the detection threshold is introduced for better tradeoff between the robustness and the sensitivity. Finally, some simulation results demonstrate that the presented states observer is robust and the fault detection for NCS is effective.     

基于热参数的燃气轮机故障诊断系统分析软件

以诊断燃气轮机(简称燃机)气路故障为目的,编写了基于热参数的燃机故障诊断系统分析软件.装有该软件的试验装置由数据采集和输出、燃机仿真、传感器故障诊断、热参数状态监控与诊断和数据库5个功能模块组成.根据数据采集模块采集到的燃机热参数,利用该软件可对燃机部件进行实时性能监测和故障诊断.应用于PG9171E型燃机的结果表明,该软件诊断精度较高,能有效对燃机运行状况进行监控和诊断.由于配备了足够多的数据采集和输出通道,并采用虚拟仪器技术替代了二次仪表,本试验装置只需对软件部分进行适当修改即可适用于航空或船用燃机.     

数据挖掘中关联规则在超市商品管理中的应用

将数据挖掘关联规则用于分析超市消费者的购物习惯和关联行为,并以此优化超市货架设置,推动关联销售,促使超市的管理决策更加科学、高效.     

Discriminant analysis based on statistical depth

<正> In the past two decades,many statistical depth functions seemed as powerful exploratoryand inferential tools for multivariate data analysis have been presented.In this paper,a new depthfunction family that meets four properties mentioned in Zuo and Serfling(2000)is proposed.Then aclassification rule based on the depth function family is proposed.The classification parameter b couldbe modified according to the type-Ⅰ error α,and the estimator of b has the consistency and achievesthe convergence rate n~(-1/2).With the help of the proper selection for depth family parameter c,theapproach for discriminant analysis could minimize the type-Ⅱ error β.A simulation study and a realdata example compare the performance of the different discriminant methods.     

修理更换策略及其比较

研究了修理更换策略，此策略是由Ｂｌｏｃｋ等提出的，在此策略下从部件最后一次修理起过一定时间就对该部件进行预防性维修。这不同于年龄更换，因年龄更换是从最后一次更换算起过去了一定时间。如果闻后一次修理是完全修理，修理更换本质上和年龄更换一样，在小修的情况，这是两个不同的策略。     

基于Sigmoid曲线拟合的亮度可控土壤图像增强

图像在相同条件下表征土壤特征会提高土壤图像识别土种的精度。对自然环境下机器视觉采集的土壤图像亮度可控增强,将不同光照条件采集的土壤图像转换为近似于该土壤在某些特定光照条件下采集的具有一定亮度的真实土壤图像,能消除或减弱光照对后续土壤图像土种识别的影响。因此,应用Sigmoid曲线对土壤图像亮度(Y)分量的累积概率密度(cumulative distribution function, cdf)曲线拟合;然后,构建目标亮度逼近优化模型,迁移拟合的Sigmoid曲线逼近目标亮度;再依据像素的邻域信息对相同亮度的像素排序、迁移,实现土壤图像的亮度可控增强;最后,利用高斯卷积核提取色调(U)、饱和度(V)分量的低频分量,并基于色比不变性原理与原始土壤图像的邻域信息对增强土壤图像的U、V分量高低频分别增强,完成颜色校正,并融合增强亮度分量,获得增强的彩色土壤图像。实验结果表明,提出算法对完全重合的亮度不同成对真实土壤图像做有目标增强实验,增强后的土壤图像与真实目标土壤图像对应像素Y、U、V分量差的标准差均值分别为14.313 7、1.323 2、2.110 5,峰值信噪比均值为29.820 9;...