Short test procedures for R-2R D/A converters by electrical modeling and application of the ambiguity algorithm

A reduced physical model of the integral non-linearity error in high resolution R-2R D/A converters is obtained by circuit analysis and application of the ambiguity algorithm. Its relationships with the well establisheda priori model based on Rademacher functions is discussed. Experiments, carried out on a sample of commercial 12 bit converters, demonstrate that functional test programs based on this model achieve shorter test times and lower prediction errors than those based on larger models obtained by straight QR factorization.     

Group Scheduling with Controllable Setup and Processing Times: Minimizing Total Weighted Completion Time

The following single machine scheduling problem is studied. A partition of a set of n jobs into g groups on the basis of group technology is given. The machine processes jobs of the same group contiguously, with a sequence independent setup time preceding the processing of each group. The setup times and the job processing times are controllable through the allocation of a continuously divisible or discrete resource to them. Each job uses the same amount of the resource. Each setup also uses the same amount of resource, which may be different from that for the jobs. Polynomial-time algorithms are constructed for variants of the problem of finding an optimal job sequence and resource values so as to minimize the total weighted job completion time, subject to given restrictions on resource consumption. The algorithms are based on a polynomial enumeration of the candidates for an optimal job sequence and solving the problem with a fixed job sequence by linear programming. This research was supported in part by The Hong Kong Polytechnic University under grant number G-T246 and the Research Grants Council of Hong Kong under grant number PolyU 5191/01E. In addition, the research of M.Y. Kovalyov was supported by INTAS under grant number 00-217.     

用阿特伍德机测量重力加速度

本文介绍了用阿特伍德机测量重力加速度的原理和测量方法。用该测量方法测量重力加速度的精度较高,而且测量的自动化程度也较高。     

Designing man–machine interactions for mobile clinical systems: MET triage support using Palm handhelds

The Mobile Emergency Triage (MET) system is a clinical triage support system that aids physicians in making triage decisions as to whether a child presenting in the Emergency Department of a hospital with a specific pain complaint should be discharged to a family physician, needs to be admitted for further investigation/observation, or requires an urgent specialist consult. The system’s mobile component is designed to work on handheld computers. This paper presents our experience and discusses our original solutions with regard to designing man–machine interactions for mobile clinical support systems. The specific interactions adopted in the MET design that are discussed in the paper were created in consultation with potential end-users and tested at the Children’s Hospital of Eastern Ontario in Ottawa.     

Single-machine and two-machine flowshop scheduling with general learning functions

We show that the O(n log n) (where n is the number of jobs) shortest processing time (SPT) sequence is optimal for the single-machine makespan and total completion time minimization problems when learning is expressed as a function of the sum of the processing times of the already processed jobs. We then show that the two-machine flowshop makespan and total completion time minimization problems are solvable by the SPT sequencing rule when the job processing times are ordered and job-position-based learning is in effect. Finally, we show that when the more specialized proportional job processing times are in place, then our flowshop results apply also in the more general sum-of-job-processing-times-based learning environment.     

相容工件系统的最小化最大延迟与误工和的重新排序

在单机重新排序问题中,一个原始工件集已经排好顺序,使得给定的目标函数最小．当一个新的工件集到来时就会产生一些错位,决策者需要插入新工件到原来排序中而还不能过分打乱它们的顺序．该论文首先研究了当工件加工时间和工期相容时,在错位量限制的条件下最小化最大延迟问题;也研究了当工件加工时间相同或工件工期相同时,在错位量限制的条件下最小化误工和问题．对这些问题,给出了好的算法．     

机床疲劳载荷的统计分析和概率设计

本文对复杂的机床传动系统的动力特性和疲劳载荷进行统计分析，对传动件的疲劳寿命也视为概率分布状态，在探讨载荷与疲劳寿命的分布规律基础上，提出了机床传动件概率设计的理论公式，用这种新的设计方法可以预测传动件的可靠度或疲劳寿命。     

固定翼飞机和直升机的分类方法研究

雷达自动目标识别是当前雷达信号处理领域的研究重点 ,而目标识别的第一步往往是将目标进行分类 ,然后再进行进一步的识别。文中研究了基于低分辨率雷达的固定翼飞机和直升机的分类问题。在分析两类飞机时域、频域特性的基础上给出了两种特征提取方法 ,利用支持矢量机进行了识别实验 ,结果表明所提出的方法是可行的。     

关于机器随机故障完工时间方差最小化单机调度问题

讨论了机器随机故障时,工件完工时间方差的期望最小化单机调度问题,其中描述机器故障的计数过程为广义泊松过程.推导出了目标函数等价的确定形式,而后进一步给出了工件加工时间相同时问题的最优解.     

变频器在工业洗衣机上的应用

本文从实用的角度介绍了变频器在工业洗衣机上的应用，介绍了工业洗衣机的动力要求，变频器的输出特性，变频器在工业洗衣机上的使用方法，以及常见问题和解决办法等．