首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 163 毫秒
1.
针对现有模糊评价方法缺乏动态可变性的不足,将可变模糊集理论引入到战略性新兴产业企业信用评价中;同时,考虑到主观赋权法与客观赋权法各有优缺点,采用基于相对熵的组合赋权法确定指标权重,从而构建了基于相对熵和可变模糊集理论的战略性新兴产业企业信用评价模型.模型克服了现有模糊评价方法的不足,较好的兼顾了赋权的主观偏好和客观信息,提高了信用评价结果的可信度、可靠性与稳健性.以20家战略性新兴产业上市公司为样本,实证分析结果说明了模型的可行性和适用性.  相似文献   

2.
一种基于图论与熵的专家判断客观可信度的确定方法   总被引:2,自引:0,他引:2  
本文给出一种群决策中确定专家判断可信度的方法,其主要思路是首先通过图论中最小生成树的方法提取专家判断矩阵的全部信息,其次,使用相对熵指标确定获得专家判断的最终结果,并同时衡量专家自身判断的统一程度,从而确定专家判断的相对客观可信度。最后,文章给出一个典型的算例以说明该方法的可行性和有效性。  相似文献   

3.
本文给出了最近在上海光学精密机械研究所LF12高功率激光装置上用KCl和CaF2真板状靶进行的类锂K和Ca离子X射线激光增益实验的结果。将要给出的还有复合X射线激光发射的时间过程和实验所用X光底片的相对标定结果。  相似文献   

4.
基于无线通信基站的三维定位相比于传统GPS定位有着诸多优势,技术有着广阔的应用前景和巨大的商业价值.针对基于无线通信基站的三维定位问题,首先分析建立TOA定位的初步模型.其次,基于对模型时钟误差、非视距传播误差、测量误差的分析,优化方程组的建立策略,基站排序,方程组系数修正的方式,使误差项的影响降到最小.最终由最小二乘法计算出定位结果.实验表明,定位模型的定位精度在1米左右,并且定位精度随基站数目的增多而增高.  相似文献   

5.
对船载特种设备基准点的空间位置进行测量,得到该基准点的运动轨迹并进行测量误差分析,是某项工程数据处理的重要内容.提出了利用三台船载GPS接收机测量船载特种设备基准点的原理和误差分析方法,介绍了该方法的误差源构成,依据测量原理模型,推导出定位精度的估算公式,并叙述了仿真计算与测量实施.  相似文献   

6.
对基于无线通信基站的室内三维定位问题进行了研究,建立了测量误差模型和终端定位模型.建立了TOA测量误差模型和基于测量误差估计的终端定位模型,提出了基于空间几何约束和测量噪声抑制的定位算法;分别在相对时间误差、最大时延、最小时延和随机法四种基站筛选方案下,分析了不同基站数目对定位精度的影响;利用轨迹上相近点的信道状态信息的相关性,采用Kalman滤波算法计算了终端运动轨迹;基于假设性检验,通过递减迭代搜索算法,得到了可定位终端数;建立了基站不同覆盖范围下,终端连接度数与定位精度之间关系的分析模型.  相似文献   

7.
针对在线评价的发布时间、获得的“有用”的投票数以及是否被贴上“砖家”点评标签对在线评价信息可信度和消费者购买决策具有重要影响,提出一种基于在线评价信息且考虑评价信息可信度及消费者类型的酒店排序方法。首先,将不同类型消费者群体给出的在线评价信息转换成考虑在线评价信息可信度的区间中智数;其次,依据区间中智数距离测度公式确定针对目标群体的各消费者群体权重,进而依据INLNPA集成算子集结各消费者群体评价信息确定针对目标群体的酒店-属性决策矩阵;再次,依据区间中智集熵测度方法确定各属性权重,在此基础上,基于VIKOR方法得到针对目标群体的酒店排序结果;最后,通过一个实例分析说明该方法的有效性和可行性。  相似文献   

8.
投影算法能较好地从宏观层面把握数据序列的接近程度,灰色关联度又恰恰可以反映数据曲线几何形状的相似性,结合投影算法和灰色关联度法的优点,弥补两种方法存在的不足,将这两种方法集成,构造出一种新的相对贴近度作为判断方案优劣的标准,提高了决策结果的可信度,避免了只引用其中某一种方案进行决策的片面性、局限性,并通过实例验证了可行性.  相似文献   

9.
以自动对比方法的智能性、自动性和可操作性为出发点,以构建弹头特征峰数据库,搭建弹头自动比对系统为目标,对弹头痕迹的自动比对问题展开研究.通过提取弹头痕迹特征线的方法,详细分析了各种影响比对的测量误差,给出了消除误差的方法.提供并实现了一种基于小波变换的比对方案,方案能够有效抑制弹头表面污损产生的噪声误差,并在实验中取得了很好的比对结果.  相似文献   

10.
模糊数是群决策中常用的决策结果表达形式.研究了模糊群决策结果的可信性评估问题.认为群决策结果的可信性与模糊群决策结果的模糊度和一致度存在强相关,因此,模糊群决策结果可信性评估主要就是对群决策结果的模糊度和一致度的计算,创新提出了基于群隶属函数的模糊度和一致度的计算方法,并给出了基于模糊度和一致度的专家模糊数决策结果综合评价值的计算方法,最后,在此基础上求得专家模糊评估结果的可信度和群决策结果的可信度.  相似文献   

11.
An Algorithm for Combined Code and Carrier Phase Based GPS Positioning   总被引:2,自引:0,他引:2  
The Global Positioning System (GPS) is a satellite based navigation system. GPS satellites transmit signals that allow one to quite accurately estimate the location of GPS receivers. In GPS a typical technique for kinematic position estimation is relative positioning where two receivers are used, one receiver is stationary and its exact position is known, the other is roving and its position is to be estimated. We describe the physical situation and give the mathematical model based on the difference of the measurements at the stationary and roving receivers. The model we consider combines both the code and carrier phase measurements. We then present a recursive least squares approach for position estimation. We take full account of the structure of the problem to make our algorithm efficient, and use orthogonal transformations to ensure numerical reliability of the algorithm. Real data test results suggest our algorithm is effective. An additional benefit of this approach is that the drawbacks of double differencing are avoided. The paper could also serve as a straightforward introduction for numerical analysts to an interesting area of GPS.This revised version was published online in October 2005 with corrections to the Cover Date.  相似文献   

12.
Bifurcation of limit cycles to a perturbed integrable non-Hamiltonian system is investigated using both qualitative analysis and numerical exploration.The investigation is based on detection functions which are particularly effective for the perturbed integrable non-Hamiltonian system.The study reveals that the system has 3 limit cycles.By the method of numerical simulation,the distributed orderliness of the 3 limitcycles is observed,and their nicety places are determined.The study also indicates that each ...  相似文献   

13.
Modularization modeling and simulation of turbine test rig main test system   总被引:2,自引:0,他引:2  
Comprehensive applications of modularization modeling method have proven its effectiveness and versatility in system simulation field. This paper establishes the modularization numerical model of a turbine test rig main test system by using a finite volume numerical system developed. The simulation study based on an experiment is conducted. The comparison with available experimental data indicates that the general trends of simulation curves are in agreement with test curves and that there is obvious thermal stratification phenomenon at different positions along combustion gas flow direction. Accordingly, it can be concluded that the analysis of experimental data is reasonable and the established numerical system is effective. It is also found that the modeling of valve spool throttling and the modeling of components-wall heat transfer are two key factors of affecting simulation accuracy.  相似文献   

14.
The determination of the pseudo-rank of a system of linear equationsis complicated by ill-conditioning and the presence of noisein the matrix elements and/or data. A method is proposed forselecting a pseudo-rank suitable for calculating approximateleast-squares solutions by considering auto-correlation propertiesof the residual vector. The method is inspired by one proposedby Powell for the fitting of curves to data, and presupposesa given ordering of the equations. The method is applied toselected ill-conditioned systems with added random noise, andthe accuracy of the calculated solutions is investigated. Pseudo-ranksdetermined by generalized cross-validation are used for comparison,and the relative accuracy of the computed solutions is considered.Results indicate that auto-correlated pseudo-rank determinationis a useful alternative to the method of generalized cross-validation,and that a combination of the two methods may yield more reliableselected pseudo-ranks.  相似文献   

15.
Fuzzy数学在涡喷发动机滑油故障诊断中的应用   总被引:1,自引:0,他引:1  
将模糊数学方法引入到涡喷发动机滑油故障诊断中 ,提出了由历史数据及专家优序数综合确定模糊隶属度的方法 ,建立了模糊诊断模型 ,解决了针对一种或数种故障征兆 ,如何准确 ,快速地找到引起故障的真正原因 ,从而为飞机的故障诊断维修工作提供了一种科学、可行的新方法 .  相似文献   

16.
In this paper, we explore the question of which non-linear inverse problems, which are solved by a selected regularization method, may have so-called linear a priori accuracy estimates – that is, the accuracy of corresponding approximate solutions linearly depends on the error level of the data. In particular, we prove that if such a linear estimate exists, then the inverse problem under consideration is well posed, according to Tikhonov. For linear inverse problems, we find that the existence of linear estimates lead to, under some assumptions, the well-posedness (according to Tikhonov) on the whole space of solutions. Moreover, we consider a method for solving inverse problems with guaranteed linear estimates, called the residual method on the correctness set (RMCS). The linear a priori estimates of absolute and relative accuracy for the RMCS are presented, as well as analogous a posteriori estimates. A numerical illustration of obtaining linear a priori estimates for appropriate parametric sets of solutions using RMCS is given in comparison with Tikhonov regularization. The a posteriori estimates are calculated on these parametric sets as well.  相似文献   

17.
网络RTK电离层误差研究现状分析   总被引:2,自引:1,他引:1  
近年来,网络RTK电离层延迟改正成为高精度实时定位中最感兴趣的研究课题之一,对基准站电离层延迟改正和改正数内插算法两个方面的主要研究内容、研究方法和研究进展进行了讨论,并探讨了目前存在的问题及探索性解决方法.  相似文献   

18.
The present work was aimed to develop a new ray tracing heat source model used in mesoscale finite volume method (FVM) simulations for the selective laser melting (SLM) process. By means of the metal-gas interface built via the volume of fluid (VOF) method, the developed model simulated the interactions between the laser beam and the powder bed. Multiple reflections of the laser beam at the surface of the metal powders were taken into account in the modeling. Integrated into the commercial software, FLOW3D, the heat source model was validated by the comparison between the calculation results and previous experiments. 3-D mesoscale simulations for the SLM process of 316 L stainless steel were performed. The result indicated that the proposed ray tracing heat source model was able to model the laser heating process of the SLM. Better than the conventional one, the new heat source model identified the local defects during the SLM process, such as the balling behavior.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号