Using RFID for the management of pharmaceutical inventory — system optimization and shrinkage control

Motivated by a case study at a radiology practice, we analyze the incremental benefits of RFID technology over barcodes for managing pharmaceutical inventories. Unlike barcode technology, RFID enables accurate real-time visibility, which in turn enables several process improvements. We analyze the impact of automatic counting and discuss the system redesign critical to optimizing the inventory policy and eliminating shrinkage. We show that continuous review is superior to periodic review whenever accurate real-time information is available at no additional cost. We explain how RFID-enabled strategies vary with inventory parameters and provide a cost-benefit analysis for the implementation of RFID for the radiology practice.     

一种新型的毫米波紧凑波导双工器

利用电路等效分析法结合全波建模提出具有宽带工作特性的改进型H面T型结。结合交叉耦合原理和一腔多模理论,通过S参数的多项式综合和矩阵消零的方法提取滤波器耦合矩阵。设计了新型结构的双模交叉耦合毫米波双工器。测试结果表明,相比于传统的单模直接耦合双工器,这种双工器不但尺寸更加紧凑,而且具有更好的频率选择性及隔离度等优点。     

异构分布式系统混合型实时容错调度算法

基/副版本技术是实现实时分布式系统容错的一个重要手段。提出了一种异构分布式混合型容错模型,该模型与传统的异构分布式实时调度模型相比同时考虑了周期和非周期调度任务。在此基础上给出3种容错调度算法:以可调度性为目的SSA算法、以可靠性为目的RSA算法、以负载均衡性为目的BSA算法。算法能够在异构系统中同时调度具有周期和非周期容错需求的实时任务,且能够保证在异构系统中某节点机失效情况下,实时任务仍然能在截止时间内完成。最后从可调度性、可靠性代价、负载均衡性、周期与非周期任务数及任务周期与粒度J个方面对算法进行了分析。模拟实验结果显示算法各有优缺点,所以在选择调度算法时应该根据异构系统的特点来选择。     

基于有限差分法求解单脊波导的并行算法研究

有限差分方法广泛应用于求解波导问题,具有易于并行的特点。为了求解大规模多脊波导场结构问题,试图从并行计算的角度提供一种有效的解决思路,给出基本算法,验证一个实例,在基本算法的基础上可进行一些必要的扩展,对求解多脊波导提供参考。     

用殷钢波导控制相控阵天线的监测精度

有效地控制某系统相控阵天线的指向精度,是保证整个系统精确定位的关键问题。这里介绍了如何利用殷钢材料的温度特性以及选用殷钢材料的波导来做监测歧管,保证监测精度的设计依据。     

基于RMS调度周期、非周期混合任务集的一种新方法*

提出了一种利用速率单调（RMS）算法确定计算机实时系统中整个任务集优先级的新方法。该方法利用数理统计的规律克服了普通RMS算法只能对系统中周期任务进行有效调度而不能对系统中的非周期任务进行有效调度的局限,扩大了RMS算法的适用范围,简化了非周期任务的处理过程,减小了系统开销。利用该方法在先进飞机电气综合控制与管理系统中进行了整个任务集的可调度性测试、验证,并给出了任务集的实际调度的验证实例。     

A metaheuristic for a teaching assistant assignment-routing problem

The Flemish Ministry of Education promotes the integrated education of disabled children by providing educational opportunities in common schools. In the current system, disabled children receive ambulant help from a teaching assistant (TA) employed at an institute for extra-ordinary education. The compensation that the TAs receive for driving to visit the pupils is a major cost factor for the institute that provides the assistance. Therefore, the institute's management desires a schedule that minimizes the accumulated distance traveled by all TAs combined. We call this optimization problem the teaching assistants assignment-routing problem (TAARP). It involves three decisions that have to be taken simultaneously: (1) pupils have to be assigned to TAs; (2) pupils assigned to a given TA have to be spread over the TA's different working days; and (3) the order in which to visit the pupils on each day has to be determined. We propose a solution strategy based on an auction algorithm and a variable neighborhood search heuristic which has an excellent performance when applied to both simulated and real instances. The total distance traveled in the solution obtained for the institute's data set improves the current solution by about 22% which represents a saving of approximately 9% on the annual budget of the institute for integrated education.     

Minimizing the number of tardy jobs in a single-machine scheduling problem with periodic maintenance

This research focuses on the problem of scheduling jobs on a single machine that requires periodic maintenance with the objective of minimizing the number of tardy jobs. We present a two-phase heuristic algorithm in which an initial solution is obtained first with a method modified from Moore's algorithm for the problem without maintenance and then the solution is improved in the second phase. Performance of the proposed heuristic algorithm is evaluated through computational experiments on randomly generated problem instances and results show that the heuristic gives solutions close to those obtained from a commercial integer programming solver in much shorter time and works better than an existing heuristic algorithm in terms of the solution quality.     

Scattering loss in optical waveguide with trapezoidal cross section

To get the scattering loss of the trapezoidal core waveguide, a new analysis model is presented based on the perturbation equivalent method and modified effective-index method. Firstly, the trapezoidal core waveguide is successfully equivalent to the rectangular one with both restricting the same optical field energy by adopting the perturbation method. Then, the equivalent rectangular core waveguide is decomposed into two slab waveguides by employing the modified effective-index method. The trapezoidal core waveguide scattering theory model is established based on the slab waveguide scattering theory. With the sidewalls surface roughness in the range from 0 to 100 nm in the single model trapezodial core waveguide, optical simulation shows excellent agreement with the results from the scattering loss model presented. The relationship between the dimension and side-wall roughness with the scattering loss can be determined in the trapezoidal core waveguide by the scattering loss model.