计算机编程语言与输入设备的发展问题初探

现代化建设事业的发展离不开计算机水平的提高。计算机编程语言作为人与机器沟通的桥梁,在计算机系统里有着非常重要的地位。本文从探讨计算机编程语言的概念出发,详细阐述了计算机编程语言所包含的内容和基本分类。接着笔者又深入分析了计算机输入设备的发展问题。最后,针对计算机编程语言和输入之间的联系问题,笔者做了观点性和理论性的论述分析。     

A fast updated algorithm to maintain the discovered high-utility itemsets for transaction modification

High-utility itemsets mining (HUIM) is a critical issue which concerns not only the occurrence frequencies of itemsets in association-rule mining (ARM), but also the factors of quantity and profit in real-life applications. Many algorithms have been developed to efficiently mine high-utility itemsets (HUIs) from a static database. Discovered HUIs may become invalid or new HUIs may arise when transactions are inserted, deleted or modified. Existing approaches are required to re-process the updated database and re-mine HUIs each time, as previously discovered HUIs are not maintained. Previously, a pre-large concept was proposed to efficiently maintain and update the discovered information in ARM, which cannot be directly applied into HUIM. In this paper, a maintenance (PRE-HUI-MOD) algorithm with transaction modification based on a new pre-large strategy is presented to efficiently maintain and update the discovered HUIs. When the transactions are consequentially modified from the original database, the discovered information is divided into three parts with nine cases. A specific procedure is then performed to maintain and update the discovered information for each case. Based on the designed PRE-HUI-MOD algorithm, it is unnecessary to rescan original database until the accumulative total utility of the modified transactions achieves the designed safety bound, which can greatly reduce the computations of multiple database scans when compared to the batch-mode approaches.     

如何设定品牌标志的设计标准

品牌设计师通过知觉联想可以将文字语言转化为直接、可见的视觉图形传达给社会大众,这种语言上的转换是设计师发掘人们想象不到或想象不全面的一种表现方式,是艺术创造。同时,在没有限制,具有广泛可能性的创意、设计中,要把企业理念和目标等文字语言浓缩、整合出适合创意、设计的关键语,这一个个关键语就是品牌标志设计的依据和标准。有了这样的设计标准就会提高设计效率和准确性,减少在标志设计过程中的矛盾与摩擦,起到指引方向和检验最终方案的作用。     

坦克设计新发展

本文提出“针对式坦克发展战略”主要内容,它要求“突破性新概念高新技术”,获得“减法设计方法”,因而形成“坦克发展新道路”.运用“系统总体取胜”的系统工程理论,处理好坦克全系统“综合”、全系统与分系统“配置”、分系统与分系统“匹配”、全系统与人及作战环境“适应”四大关系,以“相互同水平组合”替代“单项高水平爬坡”.通过“从系统总体着眼、由边际零部件突破”的途径,善于从各个部分或部件之间的结合部加以突破,实现坦克设计新发展.     

新兴本科院校理工科学生词汇学习策略调查

对新兴本科院校理工科158名学生的词汇学习观念和策略使用情况的调查表明:新兴本科院校理工科学生普遍认为词汇学习很重要,赞成边用边学;但采用的策略少于其他名校和历史悠久的本科院校的学生;其中使用频率较高的策略只有选择性注意、查词典、猜测和自我激励策略;好生与差生的词汇学习观念和策略使用存在很大的差异。     

Characterisation of rare earth minerals with field emission scanning electron microscopy

Abstract

Rare earth elements are becoming increasingly in demand, due to their prevalence in both renewable energy devices and high end electronics. The characterisation of the composition and morphology of the various phases that have valuable rare earth elements in the ores are needed in conjunction with the study of their physicochemical properties to optimise industrial process to extract the minerals containing the rare earth elements. Rare earth bearing minerals contain many elements with overlapping X-ray peaks (L- and M-lines) with an energy dispersive spectrometry detector, requiring a high degree of X-ray energy resolution. A program was developed to obtain the intensity of each peak by deconvolution of the X-ray spectrum. Low accelerating voltage of less than 5 kV and small beam diameter of less than 10 nm of a cold field emission scanning electron microscope allow x-ray microanalysis on the nanometre scale. A 100 nm wide phase was observed at 4 kV on a backscattered electron micrograph. Furthermore, a small beam diameter of less than 10 nm was used for identification of small phases of a few micrometres.

Les éléments de terre rare sont de plus en plus en demande, grâce à leur prévalence tant dans les dispositifs d’énergie renouvelable que dans l’électronique de haute gamme. On a besoin de caractériser la composition et la morphologie des différentes phases qui contiennent des terres rares de valeur dans les minerais, en combinaison avec l’étude de leurs propriétés physico-chimiques, afin d’optimiser le procédé industriel d’extraction des minéraux contenant les terres rares. Les minéraux porteurs de terre rare contiennent plusieurs éléments ayant des pics de rayons x qui se chevauchent (lignes L et M) avec un détecteur de spectroscopie à dispersion d’énergie, nécessitant une haute résolution énergétique. On a développé un programme visant à obtenir l’intensité de chaque pic par déconvolution du spectre de rayons x. Un faible voltage d’accélération de moins que 5 kV et un faisceau à faible diamètre de moins que 10 nm d’un microscope électronique à balayage par cathode froide permettent la microanalyse des rayons x à l’échelle du nanomètre. On a observé une phase de 100 nm de largeur à 4 kV sur une micrographe d’électrons rétrodiffusés. De plus, on a utilisé un faisceau de faible diamètre de moins que 10 nm pour l’identification de petites phases de quelques μm.     

The dimensional nature of same–different discrimination behavior in pigeons.

We studied the dimensional nature of same–different discrimination behavior in pigeons. Birds first learned to discriminate between simultaneously presented displays of 16 identical items (Same arrays) and 16 nonidentical items (Different arrays), conditional on the color of the background. After discrimination mastery, we tested the birds with Mixture arrays comprising both identical and nonidentical items. Accuracy increased and reaction time decreased as the disparity in entropy (a measure of variability) between the arrays increased. As well, within each entropy disparity level, lower entropy values were more discriminable than higher entropy values. These results accord with a logarithmic relation between entropy and discriminative behavior and, thus, with the idea that the discrimination of Same from Different arrays follows Weber's Law. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

基于干涉仪动态相移的光纤激光器跳模检测方法

针对已有方法在单频光纤激光器跳模检测中存在的不足,提出一种基于非平衡光纤Michelson干涉仪动态相移的跳模检测方法。使用干涉仪将激光器跳模时的光频突变转换为相位工作点的突变,并通过同步监测相位工作点的正余弦函数两路信号来跟踪与判断它的动态相移,成功实现了对超窄线宽掺铒光纤环形激光器偶发的随机跳模以及由开机瞬态热效应触发的连续多次跳模的测量与分析。结果表明,该方法检测灵敏度高,跳模判据实时直观,并能测量跳模前后可能发生的频漂,为评价单频光纤激光器的模式稳定能提供有效的测试手段。     

Hall and drift mobilities in molecular beam epitaxial grown GaAs

A series of nominally undoped and Si-doped GaAs samples have been grown by molecular beam epitaxy (MBE) with Hall concentrations ranging from 10¹⁵ to 10¹⁹ cm⁻³ and mobilities measured at 77 and 300K by Hall-van der Pauw methods. Drift mobilities were calculated using the variational principle method and Hall scattering factors obtained from a relaxation-time approximation to permit cross-correlation of experimental data with drift or Hall mobilities and actual or Hall electron concentrations. At 77K, both high purity and heavily doped samples are well represented by either drift or Hall values since piezoelectric acoustic phonon scattering and strongly screened ionized impurity scattering hold the Hall factor close to unity in the respective regimes. Between n≊10¹⁵ and 10¹⁷ cm⁻³, where lightly screened ionized impority scattering predominates, Hall mobility overestimates drift mobility by up to 50 percent and Hall concentration similarly underestimates n. At 300K, polar optical phonons limit mobility and a Hall factor up to 1.4 is found in the lowest doped material, falling close to unity above about 10¹⁶ cm⁻³. Our calculation also agrees remarkably well with the Hall mobility of the highest purity MBE grown sample reported to date.     

面向离散文本舆情分析的分聚类方案

离散文本已经成为一种占据重要地位的舆情信息表现形式,根据离散文本的特点,提出基于特征概念网的离散文本舆情信息的分聚类框架,在此基础上给出分聚类方案。在聚类算法中,运用了遗传算法的全局并行搜索能力、k—means的高效局部聚类能力和小生境的保持种群多样性抑制漂移能力;在分类算法中,先将训练文本库进行类内聚类成子类,对子类构建特征概念网以生成替代该子类的文本,再用KNN算法进行分类。最后结合舆情分析进一步提出了可用的改进方案。