缺省理论的简化

缺省理论△=(D,W)中的缺省规则集D,是该理论的不确定因素.如果能去掉一些缺省规则而又不影响该理论的延伸,则就在一定程度上简化了该理论.本文证明了关于规范缺省理论的延伸的若干性质,利用这些性质,我们可以把某些规范缺省理论在一定条件下得以化简,有的甚至可以把它们化为一阶逻辑理论.     

碾压混凝土穿透型诱导缝不同扩展阶段的强度指标试验研究

在不同削弱度碾压混凝土轴拉试件的穿透型诱导缝周围粘贴了应变片，得到在不同应力状态下诱导缝应变发展规律为：在加载初期，离缝端不同距离的应变发展较为均匀，数值上相差不突出；随着荷载的增加，应变开始出现不均匀发展，离缝端越远，应变变化越缓慢；当接近最大荷载的阶段，缝端应变急速发展，试件瞬间断裂。应变从均匀发展变为不均匀发展，实质上隐含了诱导缝起裂、稳定发展、失稳断裂的整个过程，针对这一试验现象，结合断裂力学理论，建立了诱导缝不同开裂阶段的远场温度应力强度指标模型。     

电容传感器在使用中存在的几个问题及处理方法

随着电容测量技术的迅速发展，电容传感器在非电量测量和自动检测中得到广泛应用，但它在使用过程中也存在一些问题，针对在使用电容传感器过程中存在的几个问题，从电容传感器的原理和工作过程两个方面进行了讨论，并提出行之有效的处理方法。     

Efficient reconfigurable techniques for VLSI arrays with 6-port switches

This paper proposes an efficient techniques to reconfigure a two-dimensional degradable very large scale integration/wafer scale integration (VLSI/WSI) array under the row and column routing constraints, which has been shown to be NP-complete. The proposed VLSI/WSI array consists of identical processing elements such as processors or memory cells embedded in a 6-port switch lattice in the form of a rectangular grid. It has been shown that the proposed VLSI structure with 6-port switches eliminates the need to incorporate internal bypass within processing elements and leads to notable increase in the harvest when compared with the one using 4-port switches. A new greedy rerouting algorithm and compensation approaches are also proposed to maximize harvest through reconfiguration. Experimental results show that the proposed VLSI array with 6-port switches consistently outperforms the most efficient alternative proposed in literature, toward maximizing the harvest in the presence of fault processing elements.     

Reliability evaluation of class-E and class-a power amplifiers with nanoscaled CMOS technology

Circuit reliability of class-E and class-A power amplifiers is investigated based on a newly developed degradation subcircuit model. Measured degradation characteristics on the fabricated circuits agree well with the simulation predictions. Using this model, we have found that the class-E amplifier degrades faster than a class-A amplifier, due to a much higher stress level during switching. With a drastic decrease of PAE, a shorter lifetime is expected for a class-E amplifier.     

An experimental study of an optical burst switching network based on wavelength-selective optical switches

In this article we report the system structure and test results of an experimental optical burst switching network with three edge router's and one core node. Wavelength-selective switches developed for this system and their characteristics are depicted. The implementation and performance of our new scheme for the just-in-time protocol are described. We also report experimental results of FTP and VOD services on this system. Some parameters, including traffic rate, average burst data length, and assembly time, are studied.