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1.
本文采用多元统计分析,对地面遥感图象进行主成分分析、聚类分析和主成分回归分析,给出遥感图象对代表的污染源的浓度的半定量化估计结果。本文所提供的方法是对国际通用的污染源监测的林德曼(Lindemann)定性估计方法的改进和精确化.为大气环境质量监测和评价,以及研究污染源排放行为提供了新途径. 本文引入了统计综合评判模型.用来解译遥感信息达到国际水平,应用到实际环保部门取得了一定的社会效益和经济效益.  相似文献   

2.
本文介绍了主成份分析法在检验体育多科教学效果中的应用。本文对几届 学生追踪使用主成份分析法,分析教学效果的变化,发现:1.用主成份法检验 多科教学效果很好;2.一般师范体育教学格局为:全面发展素质基础和技术为 主,艺术表现为辅。本文受南京师范大学青年科技基金支持。  相似文献   

3.
崔文泉、李娟.对球面工件的一种新测量方法的最优设计研究.本文针对一种新的适用于车间在线测量的球面工件测量方法———气动方式的多测头、多测点的方法进行了布点最优设计的研究,给出了布点设计的最优性条件、使被测球半径达到最大精度的设计等,最后给出了设计示例  相似文献   

4.
本文指出测点很多吋,求解多项式趋势面次数很低的原因;详细论证提高求解次数的方法及其在矿产资源评价计算中的成功应用.  相似文献   

5.
本文应用主成分析的基本方法,结合单质量特性的工序能力指数,给出了多质量特性的主成份的工序能力指数。  相似文献   

6.
数学解题过程主要就是化繁为简、化难为易的转化过程,在众多的转化方法中,主元法是一种重要的方法.主元法就是在数学问题所涉及的常量、参量、变量等多个量中,选择一个量作为主要变元,并以此为解题的主线,从而实现数学问题的转化,使问题得以解决的思想方法.在与函数、方程、不等式相关的问题中应用广泛,往往能起到另辟蹊径,突破思维障碍的妙用.使用主元法解题的关键是主元的确立,本文意图对这一问题加以探讨.  相似文献   

7.
本文介绍了数量经济学中的一些基本概念,以及主成分分析在经济波动研究中的应用,并结合例子介绍了经济波动的频率域分析,详细介绍了一种区间控制计量经济模型.  相似文献   

8.
本文中应用线性算子扰动理论研究了胎次递进人口算子在递进比的小扰动下对主本征值及相应本征元的影响,给出了主本征值及相应本征元的修正值主项所满足的公式.  相似文献   

9.
关于线性回归模型的有偏估计   总被引:3,自引:0,他引:3  
有偏估计方法是近代回归分析的常用方法.本文研究了几种常用的有偏估计方法,澄清了这些方法的区别和联系.对有偏估计的一些关键点进行研究,给出了一种新的岭参数确定法和一种新的主成分概念,并讨论了这些方法的优良性.为了提高有偏估计的效率,提出了用比例因子规范模型的方法.最后,给出了说明本文方法的数值例子.  相似文献   

10.
结合分析的原理和应用   总被引:10,自引:1,他引:9  
沈浩,柯惠新.结合分析的原理和应用.数理统计与管理,1998,17(4),39~45.结合分析用来分析消费者对产品/服务的偏好。本文通过对采用部分因子设计估计主效应的全轮廓法以及用一般最小二乘法(OLS)回归计算属性水平的效用分析,介绍了这种结合分析法的概念、步骤和应用  相似文献   

11.
In this paper we develop an open queueing network for optimal design of multi-stage assemblies, in which each service station represents a manufacturing or assembly operation. The arrival processes of the individual parts of the product are independent Poisson processes with equal rates. In each service station, there is a server with exponential distribution of processing time, in which the service rate is controllable. The transport times between the service stations are independent random variables with exponential distributions. By applying the longest path analysis in queueing networks, we obtain the distribution function of time spend by a product in the system or the manufacturing lead time. Then, we develop a multi-objective optimal control problem, in which the average lead time, the variance of the lead time and the total operating costs of the system per period are minimized. Finally, we use the goal attainment method to obtain the optimal service rates or the control vector of the problem.  相似文献   

12.
大力发展和推广纯电动汽车已成为全世界众多国家的共同选择。但电动汽车有限的续航能力及公共快速充电设施的缺乏,制约着人们的使用和长途出行。本研究针对我国公共快速充电网络建设亟待完善的问题,基于我国主干高速公路网络,对服务途中充电需求的快速充电站科学分布问题建立分布决策模型。研究表明,对续航能力低于200公里的电动汽车,应用最优策略分布的快速充电站数量从50座增加到250座时,可将途中充电需求覆盖率从50%左右提高到90%以上,而对续航能力超过250公里的电动汽车,150座按最优策略分布的快速充电站即能覆盖至少96.49%的途中充电需求。通过对不同续航能力和不同充电站数量约束下共30种情形的分析,本研究不仅能为多情形下充电站分布问题提供最优选址和数量组合决策方案,也为我国充电基础设施的完善及电动汽车产业可持续发展提供有力的理论支持和政策建议。  相似文献   

13.
We consider a two-stage tandem queueing network where jobs from station 1 join station 2 with a certain probability. Each job incurs a linear holding cost, different for each station. Each station is attended by a dedicated server, and there is an additional server that is either constrained to serve in station 1 or can serve in both stations. Assuming no switching or other operating costs for the additional server, we seek an allocation strategy that minimizes expected holding costs. For a clearing system we show that the optimal policy is characterized by a switching curve for which we provide a lower bound on its slope. We also specify a subset of the state space where the optimal policy can be explicitly determined.  相似文献   

14.
We consider optimal scheduling problems in a TSSS (Time Sharing Service System), i.e., a tandem queueing network consisting of multiple service stations, all of which are served by a single server. In each station, a customer can receive service time up to the prescribed station dependent upper bound, but he must proceed to the next station in order to receive further service. After the total amount of the received services reaches his service requirement, he departs from the network. The optimal policy for this system minimizes the long-run average expected waiting cost per unit of time over the infinite planning horizon. It is first shown that, if the distribution of customer's service requirement is DMRL (Decreasing Mean Residual Life), the policy of giving the highest priority to the customer with the most attained service time is optimal under a set of some appropriate conditions. This implies that any policy without interruptions and preemptions of services is optimal. If the service requirement is DFR (Decreasing Failure Rate), on the other hand, it is shown that the policy of giving the highest priority to the customer with the least attained service time, i.e., the so-called LAST (Least Attained Service Time first) is optimal under another set of some appropriate conditions. These results can be generalized to the case in which there exist multiple classes of customers, but each class satisfies one of the above sets of conditions.  相似文献   

15.
三维定位问题是现代商用通信网络中对于定位系统存在的一个真正具有技术难度的挑战.根据视距传播环境和非视距传播环境的到达时间的数据集,建立线性误差模型;对于无真实位置的竞赛数据集,定义竞赛数据定位误差评估模型;基于不同的空间场景,提出基于空间单元的定位算法;面对高度误差明显高于平面误差的问题,设计基于高斯加权的误差补偿模型;针对最优定位精度最少基站问题,提出基于贪心策略的基站选择算法;考虑轨迹连续性,设计轨迹准确性验证的10-fold交叉验证方法;基于测量距离有限的真实环境,分析平均"连接度数"与定位精度的关系.实验结果表明,提出的定位算法在有效基站数大于等于5时,能获得较好的定位精度.  相似文献   

16.
We study the optimal dynamic assignment of a single server to multiple stations in a finite-population queueing network. The objective is to maximize the long-run average reward/throughput. We use sample-path comparisons to identify conditions on the network structure and service time distributions under which the optimal policy is an index policy. This index policy assigns the server to the non-empty station where it takes the shortest amount of time (in some stochastic sense) to complete a job. For example, in a network of multiple parallel stations, the optimal policy assigns the highest priority to the fastest station if service times can be ordered in likelihood ratios. Finally, by means of a numerical study, we test the shortest-expected-remaining-service-time policy on parallel-series networks with three stations and find that this index policy either coincides with the optimal policy or provides a near-optimal performance.  相似文献   

17.
We consider a queueing network with two single-server stations and two types of customers. Customers of type A require service only at station 1 and customers of type B require service first at station 1 and then at station 2. Each server has a different general service time distribution, and each customer type has a different general interarrival time distribution. The problem is to find a dynamic sequencing policy at station 1 that minimizes the long-run average expected number of customers in the system.The scheduling problem is approximated by a dynamic control problem involving Brownian motion. A reformulation of this control problem is solved, and the solution is interpreted in terms of the queueing system in order to obtain an effective sequencing policy. Also, a pathwise lower bound (for any sequencing policy) is obtained for the total number of customers in the network. We show via simulation that the relative difference between the performance of the proposed policy and the pathwise lower bound becomes small as the load on the network is increased toward the heavy traffic limit.  相似文献   

18.
针对道路堵塞如节假日导致的临时最短配送路径失效的问题,提出配送网络最优路径选择模型,并设计了求解快递配送网络关键边和最优路径的算法。首先,计算出整个网络的关键边,掌握配送网络特征;其次,考虑顾客时间要求,研究不完全信息(中断无法提前预知,只有到达中断边的起点处才可知)下的最优路径,根据最短路径上各边新的特点,计算出每条边中断后对应的一组备用路径,再选择运输时间小于或等于顾客可等待时间的路径为有效路径,考虑道路堵塞情况,从有效路径中选择最优路径;最后,结合配送网络的实际情况对最优路径进行了算例分析。  相似文献   

19.
We compute the distribution of the time for a two-stations walk in an open Jackson network (which includes the twofold service at one station), and give a simple derivation of the distribution of the sojourn times for overtake-free paths in these networks.  相似文献   

20.
We examine a class of problems in queueing networks which arise when customers enter a bank of parallel servers in a given order and lose their place in the sequence due to passing resulting from variations in service times. The original sequence is required before service can take place at the next station in the network. These problems arise naturally in flexible manufacturing systems. The result is that the next station beyond the parallel bank of servers can be approximated by a non-Markovian bulk arrival system. This station sees batch arrivals of customers that are eligible to receive service. The size of the arriving batches is shown to depend on the inter-arrival times. Several fundamental results are established for this class of problems including the distribution of batch inter-arrival times, batch sizes, and an approximate method for determining the distribution of the number of eligible and an exact method for determining the distribution of the number of ineligible customers in the system.  相似文献   

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