数字放大器—3G无线基站的助推器

为了构筑第三代无线网络,人们需要对现有基础设施进行彻底改造,包括网络的发射基站。配置在无线基站中的新型数字控制功率放大器能够改善频谱利用率和功率效率,从而提高系统容量。PMC-Sierra公司的数字控制功率放大器采用了数字校正信号处理器(DCSP)以及自适应控制处理器和补偿估值器(ACPCE),该放大器可改善无线基础设施的可靠性,同时降低系统成本、规模及复杂性。     

A stochastic maximum principle for systems with jumps, with applications to finance

We consider a stochastic control problem with linear dynamics with jumps, convex cost criterion, and convex state constraint, in which the control enters the drift, the diffusion, and the jump coefficients. We allow these coefficients to be random, and do not impose any L^p-bounds on the control.

We obtain a stochastic maximum principle for this model that provides both necessary and sufficient conditions of optimality. This is the first version of the stochastic maximum principle that covers the consumption–investment problem in which there are jumps in the price system.     

Ultrasonic measurement of the inter-electrode gap in electrochemical machining

During the process of electrochemical machining the dependency of the inter-electrode gap with time and process parameters can be used to determine process characteristics and to define the shape of the workpiece surface relative to the tool surface. Defining process variables to map out the required gap-time function requires the use of time-consuming iterative trials. In-line monitoring of the gap would enable process control and tool to workpiece transfer characteristics to be achieved (for ideal conditions) without the requirement to generate such parameter maps. This work explores the use of ultrasound applied as a passive, non-intrusive, in-line gap measurement system for ECM. The accuracy of this technique was confirmed through correspondence between the generated gap-time and current time data and theoretical models applicable to ideal conditions. Gap measurements are also used to demonstrate and quantify the degree of departure from ideal behaviour for an In718/chloride system as the electrolyte flow rate is reduced from 16 to 4 l min⁻¹. The monitoring of the gap size has also been shown to be effective when determining shape convergence under ideal conditions, for the example case of a 2D sinusoidal profile.     

气相色谱在线分析变压吸附法制纯氢中的总碳

利用带镍加氢转化炉的气相色谱仪 ,在线分析变压吸附法制纯氢中的总碳。该法用变压吸附法制的纯氢作燃气 ,在检测器前端将氢气中的CO和CO2 转化为CH4,然后用氢火焰离子化检测器检测 ,直接以检测器的信号 (mV)进行定量。当氢气中总碳体积分数在 1 9～ 5 0 0 μl/L时 ,FID信号值与总碳体积分数有良好的线性关系。方法回收率为 99 90 %～ 10 1 9%,相对标准偏差 <1%。     

Model checker aided design of a controller for a wafer scanner

For a case-study of a wafer scanner from the semiconductor industry it is shown how model checking techniques can be used to compute (1) a simple yet optimal deadlock avoidance policy, and (2) an infinite schedule that optimizes throughput. in the absence of errors. Deadlock avoidance is studied based on a simple finite state model using Smv, and for throughput analysis a more detailed timed automaton model has been constructed and analyzed using the Uppaal tool. The Smv and Uppaal models are formally related through the notion of a stuttering bisimulation. The results were obtained within 2 weeks, which confirms once more that model checking techniques may help to improve the design process of realistic, industrial systems. Methodologically, the case study is interesting since two models were used to obtain results that could not have been obtained using only a single model. Supported by the European Community Project IST-2001-35304 (Ametist), http://ametist.cs.utwente.nl/.     

基于Agent的分布式查询优化研究

Internet上异构的软硬件环境以及多种并行机制对分布式查询优化技术提出了新的挑战，文章将分布式人工智能与数据库管理系统两个研究领域相结合，给出了基于Agent的分布式查询优化系统模型，在该系统中，Agent采用了典型的慎思型体系结构，即BDI模.Agent具有信念库，目标库并在此基础上进行学习和推理，多个Agent之间通过协调，协作以及协商以支持分布式数据库系统的动态查询优化和规划的执行，提高系统的查询效率。     

我国企业开展流程再造应从工作研究开始

由于管理基础工作薄弱，我国很多企业流程再造的努力未获成功。基于企业流程再造与工作研究之间的对比分析，文章提出了运用工作研究领域内的有关理论、经验、方法和工具来帮助我国企业开展流程再造。     

疏浚吹填工程推行项目经理责任承包制管理模式的探讨

阐述了传统管理模式的生存条件及其弊端,对疏浚吹填工程推行项目经理责任承包制管理模式进行了探讨.     

圆形槽波导波长计的研究¹

圆形槽波导与高Q谐振腔相耦合可以用作毫米波波长计，本文应用网络分析和等效电路的方法对圆形槽波导波长计中的耦合结构进行了理论分析和计算。     

发电机用DJL350磁极钢板的开发与应用

本文论述了高强度冷轧磁极板的试制性研究，应用性研究及在开生桥机组上的实施。通过与国外材料的对比，研究了材料的化学成分、力学性能、磁性能、金相组织及其与性能的关系。并对其实际应用效果进行了分析总结。