应用于音乐节目分类的Apriori挖掘算法设计

传统Apriori挖掘算法需多次扫描数据库、多次连接频繁项集,导致挖掘效率较低,为此对Apriori挖掘算法加以改进,设计一种新的Apriori挖掘算法用于音乐节目分类。改进的Apriori挖掘算法采用莱特准则对音频数据进行野值与噪声平滑处理,改进Apriori挖掘算法的音频数据库映射令两个线性表分别负责音频数据存储和对应项存储,音频数据库扫描次数降为一次;改进Apriori挖掘算法的连接次数无需对不具备交运算能力的元素进行交运算操作,减少频繁项集连接次数。基于改进频繁项集Apriori挖掘算法挖掘频繁项集、生成音频数据关联规则,基于关联规则集构建分类器,实现音乐节目分类。实验结果显示,改进Apriori挖掘算法用于音乐节目分类的效率优势突出,准确度高。     

改进的Apriori算法在试题关联分析中的应用

针对关联规则挖掘中经典Apriori算法由于多次扫描数据、产生大量候选集及产生候选集时连接次数多等缺陷,导致效率较低。文中提出删除部分特殊事务,减少扫描数据次数。在生成候选k-项集前,对频繁k-1项集进行约简,减少连接次数和候选k-项集数,对Apriori算法进行改进。并将改进的Apriori算法用于试题分析中,得出试题之间的关联关系。实例表明,改进后的算法在效率上优于Apriori算法。     

一种基于矩阵的Apriori改进算法

Apriori算法是经典的关联规则挖掘算法之一。该算法可以很好地挖掘关联规则,通过连接步和剪枝步从频繁项集中获取候选项集,但产生大量的候选项集,这就需要重复扫描数据库,大大增加算法运行时间。文中提出一种基于矩阵的改进算法,通过事务矩阵和候选项集项目矩阵相乘的矩阵操作来改进频繁扫描数据库的问题。事务数组的建立可以删除不能生成下一频繁项集的事务,删除不必要的项,针对频繁项集的产生过程优化Apriori算法的连接步和修剪步。在不同的数据集下通过实验验证改进算法不仅能准确地挖掘出频繁项集而且大大地缩短挖掘时间。     

基于布尔矩阵Apriori算法的改进研究

为了高效且快速地从事务数据库中生成频繁项集,在研究基于布尔矩阵Apriori算法的基础上,提出一种改进算法PM Apriori(Prune Matrix Apriori)算法。此算法充分利用矩阵的存储与运算特性,仅扫描数据库一次,不需要生成候选集,有效地提高算法的运算效率,在算法执行过程不断对存储矩阵进行修剪压缩,节省了内存空间和扫描矩阵的时间,并通过算法示例与算法性能对比分析证明所提出的改进算法具有良好的时间特性和空间特性。     

改进的Apriori算法在股票联动中的应用

针对原始Apriori算法在计算二项频繁集时产生大量无效的候选集,以及对候选集进行了冗余的扫描这两个问题,文中提出一种改进算法LZ-Apriori,能够大大提升Apriori算法在计算二项频繁集过程中的时间效率,进而加速整个运算过程。将新算法运用到沪深股市板块联动的规则挖掘中,证实了新的算法具有良好的改进效果。     

关联规则挖掘 Apriori 算法的研究与改进

针对传统Apriori算法的不足之处,提出两种Apriori改进算法,分别基于构造辅助表和项集求交集策略。改进算法大幅度减少扫描数据库的次数,缩减对不必要事务的扫描时间,显著提高频繁项集的生成效率,从而使算法达到更高的运算效率。实验结果表明,两种改进算法都是有效的关联规则挖掘方法,且比Apriori算法性能更优,亦为关联规则挖掘研究提供了一些科学可行的新思路。     

基于子集的Apriori算法在MapReduce下的研究

文中在频繁项目集挖掘研究的基础上,针对Hadoop分布式计算框架,提出了一种基于子集的Apriori并行改进算法Sub Apr。该算法扫描数据库两次,将分块数据分配给不同的Hadoop计算节点进行处理,利用Apriori特性并结合MapReduce框架自身特点进行剪枝。该算法与同类算法比较,可以减少各个计算节点的存储数据,达到减少候选项集输出,有效减少了大数据集挖掘过程中产生的大量数据通信,从而提高并行挖掘的效率。实验结果表明,该算法是有效且可行的。     

基于位运算和倒排索引的关联规则挖掘算法

提出了一种改进的Apriori关联规则挖掘算法,称为Apriori-BR。该算法首先通过扫描两次数据库建立各个频繁项目集到事务的倒排索引,并对倒排索引按照事务长度进行分组,然后在挖掘过程中,利用位运算加快子集的检测,并在必要时动态删除无效的低维事务。实验结果表明,相比于经典的Apriori算法和已有文献中的改进算法,本文所提的Apriori-BR算法显著提高了挖掘效率。     

基于改进的遗传算法的关联规则挖掘

Apriori算法是挖掘关联规则频繁项集的经典算法,但需要对数据库进行多次扫描,在交易量较大的情况下,严重地影响了算法效率。本文将改进的遗传算法应用于求解频繁项集,解决了这一问题。实验表明,该算法具有一定的推广价值。     

一种基于上三角频繁项集矩阵的频繁模式挖掘算法

提出了一种高效挖掘数据的频繁项目集模式的算法FIA.该算法采用一种二进制符号来表示数据,在仅扫描数据库一次之后,建立起二进制向量与上三角频繁项集矩阵,根据两者来产生出频繁项集.从而有效地缩小了搜索空间,加快了处理速度.通过实验表明,FIA算法比Apriori算法更有效.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

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.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

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.     

An improved parallel thinning algorithm with two subiterations

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.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.