通讯网络中极小费用生成树的一种算法

针对具有n个通讯站的局域网络,运用增加或调整虚设站的方法,给出一种在混合距离下的极小费用生成树的算法.并就MCM91问题B,求出了极小费用生成树,其总费用小于美国马里兰州里斯勃来莱州立大学数学科学系B.A.Fusaro所提供的论文中的费用.     

一种高效的2.45 GHz二极管阵列微波整流电路

 采用4只HSMS 282肖特基二极管阵列,对大功率微波整流电路进行了研究。构造了基于微带线结构的2.45 GHz高效微波整流电路,将微波整流单元电路的输入功率提升到33 dBm。仿真和实验结果表明,在一定微波输入功率的条件下,整流电路在负载较大范围内变化时保持了高整流效率。通过在不同微波输入功率和负载下进行测量,发现当输入微波功率为27.0~31.7 dBm之间变化时,最高整流效率均达到了60%以上,当微波输入功率为30 dBm时,微波整流电路效率达到了63.3%。     

Approximate performance measures for a single station two-stage reneging queue

We study a single station two-stage reneging queue with Poisson arrivals, exponential services, and two levels of exponential reneging behaviors, extending the popular Erlang A model that assumes a constant reneging rate. We derive approximate analytical formulas representing performance measures for our two-stage queue following the Markov chain decomposition approach. Our formulas not only give accurate results spanning the heavy-traffic to the light-traffic regimes, but also provide insight into capacity decisions.     

Modelación numérica de la descarga térmica de la Central Nucleoeléctrica Laguna Verde

This work contributes to the study of nuclear plant thermal discharges in coastal areas by using a numerical model which solves the Navier-Stokes-Reynolds equations for shallow waters and the energy equation for computing temperature variations. The numerical model takes into account the heat flux given in the upper layer, where the free surface and the atmosphere interact. In this study, the thermal plume dispersion from the nuclear power plant Laguna Verde, Veracruz, Mexico, is analyzed. Bathymetry, oceanographic, meteorological, hydrologic and plant operating data are used to run numerical simulations. The results are compared against observed data showing good agreement. The Nash-Suffle's criterion is also applied to verify the quality of the numerical solution obtaining suitable results.     

无线电导航差分技术应用初探

本文对应用孚分技术控制长河一号的时羞偏差，提高定位精度的可行性.进行了初步研-lL.首次试验表明:系统的时差偏差可从+7.3微秒减少至+1.2微秒，精度提高五倍;系统的羊分监测站有效监控范围可达68.9海里;时差变幅与分差精度无关.     

谱仪专用计算机Aspect—3000与IBM—PC微机的数据传输及处理

本文首先介绍了利用Kermit程序在谱仪专用计算机Aspect和通用微机IBM-PC之间进行数据通讯的方法,然后提供了几则应用实例。特别是在IBM-PC上配备数据处理程序后,它即可成为谱仪的卫星数据站。     

论类梯度筛选算法的无效性

本文简要介绍了水能资源梯级开发顺序最优化研究中著名的“类梯度筛选算法”,在实践中给出了该算法的一个反例,并在理论上证明了该算法的无效性.     

Application of a location model to fire stations in Rotterdam

This report is an outgrowth of a research project carried out by the Operations Research Group of Twente University of Technology in cooperation with the Department Fire-Brigade Affairs (Home Office) and the Rotterdam Fire Department. The objectives of the project were to determine the minimal number of fire stations, their locations and the number of first attendance pumpers, so that each point in town can be reached within a prescribed attendance time with sufficient equipment.A road network approach was used for determining the set of possible location areas for fire stations followed by a set-covering approach for calculating the minimal number of stations. The hard points to tackle were the construction of robust networks, the determination of the possible location areas and the calculation of all the alternative locations of a minimal number of fire stations.A simulation was carried out to test whether the solutions given by the network approach were realistic.     

Perkin—Elmer公司DSC-2C差示扫描量热仪数据处理站的改进与功能扩展

介绍了对Ｐｅｒｋｉｎ－Ｅｌｍｅｒ公司生产的ＤＳＣ－２Ｃ差示扫描量热仪数据处理站专用计算机原程序进行修改的工作，并与通用微机联用，改进了原数据处理站的输出方式，扩展了数据处理功能。     

南极中山站宁静日午后极光事件分析

对１９９７ 年６ 月２ 日１１２７～１７００ ＵＴ,在南极中山站（不变地磁纬度为７４．５Ｓ,ＭＬＴ＝ ＵＴ＋ ２）利用全天空极光摄像机和三波段极光扫描光度计观测到的午后极光进行了分析,发现宁静日午后极光的形态随磁地方时变化．在午后早些时候,辉度较弱的冕状极光出现在中山站的极向侧和日向侧;随后出现的是来自日侧的带状极光,该结构东向传播,赤道向运动;在午后较晚的时候出现的是来自夜侧的带状极光．同时将午后极光与当地地磁观测、ＤＭＳＰ／Ｆ１１ 卫星的粒子观测以及ＷＩＮＤ卫星的ＩＭＦ观测进行了对照分析,认为宁静日午后极光中的分离结构是由来自磁层顶附近的粒子沉降产生的,其变化和运动与地磁Ｈ 分量和ＩＭＦＢｚ 分量的变化相关．