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1.
针对不完备信息系统条件下的辐射源威胁等级判定问题,提出了一种基于改进容差关系粗糙集(ITR-RS)的不完备信息系统辐射源威胁等级判定方法。该方法将粗糙集中的不完备信息系统理论引入辐射源威胁等级判定中,并构建一套完备的决策规则提取模型。此外,利用辨识矩阵实现对属性的约简,在降低系统所需处理数据量的同时,提高了算法的实时性;在容差关系粗糙集的基础上,提出一种改进的容差关系,在属性主、客权重相结合的基础上引入阈值来划分加权阈值容差类,得到更为合理、准确的决策规则。仿真试验及分析表明,与经典RS算法相比,所提算法的威胁等级判定正确率提高了23%,可用于信息系统不完备条件下的辐射源威胁等级判定。  相似文献   

2.
基于不完备信息系统的粗模糊属性值的知识获取   总被引:2,自引:2,他引:0  
研究了一类基于粗集属性取模糊值的不完备信息系统的知识获取方法.给出粗模糊属性值信息系统的一种表示方法,采用模糊集思想,构造这类系统的模糊不可分辨关系,并研究这类信息系统的知识获取算法,并以一个实例,说明这种算法的有效性.  相似文献   

3.
韩红旗 《信息技术》2009,(10):27-29
在Rough集理论中,利用信息表通过数据预处理、属性约简、值约简等处理后,可以得到一组决策规则知识,其应用能够大大提高决策水平,但这些获取的知识完全建立在数据源的支持上。数据源在产生和处理的过程中容易受到一些事件或人为因素影响,因此所得到的规则知识可能和现实存在一定的偏差,如果不加处理将其直接应用于逻辑推理系统,可能影响决策的质量和效果。为此,提出了数据支持度、专家支持度和规则可信度的概念,引入专家的经验判断,利用专家的知识对获取的规则知识进行评价,形成规则知识可信度的排序,然后去除不可靠的规则知识,得到了具有较高可信度和实际应用价值的决策规则知识。  相似文献   

4.
连续值属性决策表中的知识获取方法   总被引:3,自引:1,他引:2  
冯林  王国胤  李天瑞 《电子学报》2009,37(11):2432-2438
 提出了一种从连续值属性决策表中获取知识的方法KACVA(Knowledge Acquisition from decision tables containing Continuous-Valued Attributes).该方法将经典粗糙集理论对数据空间的等价划分转换为相似划分,把传统粗糙集理论中正域的表示方法扩充到连续值属性决策表中;通过计算连续值属性决策表中各条件聚类对决策类的分类能力,生成决策规则.不同数据集的实验测试结果表明:对连续值属性决策表中的知识获取,KACVA方法与传统的粗糙集相关知识获取方法及C4.5决策树分类方法相比,有更高的分类准确率.  相似文献   

5.
该文在研究粒计算理论的基础上,提出了一种基于粒计算的增量式知识获取方法。该方法通过建立决策信息系统原始的知识粒树,对新增数据,在原始知识粒树中查找相匹配的知识粒,并依据决策值更新知识粒树,实现快速高效地处理动态信息系统。算法分析及实验对比结果表明,该方法在动态信息系统知识获取方面优于RGAGC和ID4方法。  相似文献   

6.
在不完备信息系统中引入决策属性依赖度,由条件属性所提供的知识对整体决策的支持程度,以此作为启发式信息求出相对核,使属性约简具有较强的支持度。文章通过实例分析,证明该属性约简是有效的方法。  相似文献   

7.
基于粗糙集的交通信号控制决策研究   总被引:1,自引:1,他引:0  
郑梦泽 《通信技术》2010,43(4):225-227
粗糙集理论能够在分析大量经验数据基础上找到用于判断决策的规则,同时允许决策对象中存在一些不太完整的属性,并通过推理得出基本上确定的规则。将粗糙集理论与交通控制结合起来,对交通控制过程中的属性进行了分析,并将粗糙集理论的知识获取和决策分析算法应用到交通信号控制中,提出了一种系统的交通信号控制知识获取和决策的方法,是在解决城市交通状况决策问题上的一次有益的尝试。  相似文献   

8.
不完备信息系统中知识约简的一种启发式算法   总被引:6,自引:0,他引:6  
不完备信息系统中的知识获取是粗集理论应用的难点。通过引入信息熵和条件信息熵,对信息系统中属性的必要性进行了定义;提出了一种基于条件信息熵的知识约简启发式算法,并指出该算法的时间复杂度是多项式的。通过实例说明,该算法能得到信息表的约简和决策表的最小相对约简。  相似文献   

9.
谭静  丁香乾 《现代电子技术》2012,35(14):120-122,130
比较分析了已有扩充粗糙集模型,提出基于相似度的变精度容差关系扩充粗糙集模型。该模型根据两对象的相似度及属性值缺失情况划分客差类。通过与基于容差关系、相似关系、限制容差关系等扩充粗糙集模型比较,证实了该模型对不完备信息系统处理的现实可行性和有效性,最后给出了相对正域的概念及属性约简规则。  相似文献   

10.
在传统的故障诊断专家系统的基础上,引入粗糙集理论以解决专家系统较难获取完备知识系统的瓶颈问题。该系统从历史故障数据所形成的决策表出发,通过粗糙集数据挖掘算法获取故障诊断的最小约简属性集和潜在的诊断规则,并建立诊断规则知识库。通过计算规则隶属粗糙度来表示诊断规则的置信程度。本文中以YYBC-2型航空液压油泵车液压系统中的故障诊断分析为例进行了验证。  相似文献   

11.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

12.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

15.
In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.  相似文献   

16.
High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.  相似文献   

17.
This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.  相似文献   

18.
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.  相似文献   

19.
A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.  相似文献   

20.
An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.  相似文献   

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