Maintaining statistics counters in router line cards

A network device stores and updates statistics counters. Using an optimal counter management algorithm minimizes required SRAM size and ensures correct line-rate operation for many counters. We use a well known architecture for storing and updating statistics counters. This approach maintains smaller-size counters in fast (potentially on-chip) SRAM, while maintaining full-size counters in a large, slower DRAM. Our goal is to ensure that the system always correctly maintains counter values at line rate. An optimal counter management algorithm (CMA) minimizes the required SRAM size while ensuring correct line-rate operation for a large number of counters     

基于分布特征统计的说话人识别

给出了基于公共码书的说话人分布特征的定义。提出了基于分布特征统计的说话人识别算法,根据所有参考说话人的训练语音建立公共码书,实现对语音特征空间的分类,统计各参考说话人训练语音的在公共码字上的分布特征进行建模。识别中引入双序列比对方法进行识别语音的分布特征统计与参考说话人模型间的相似度匹配,实现对说话人的辨认。实验表明,该方法保证识别率的情况下,进一步提高了基于VQ的说话人识别的速度。     

Order statistics of the generalized logistic distribution

The generalized logistic distribution function studied here, (1 + e^-χ)^-α, has parameter α 2#62;; 0 and is defined for all real χ. This distribution is useful for modeling the log odds of moderately rare events. Estimation of α by functions of order statistics is discussed. The distribution and moments of the order statistics and the sample range are also derived.     

Seesoft-a tool for visualizing line oriented software statistics

The Seesoft software visualization system allows one to analyze up to 50000 lines of code simultaneously by mapping each line of code into a thin row. The color of each row indicates a statistic of interest, e.g., red rows are those most recently changed, and blue are those least recently changed. Seesoft displays data derived from a variety of sources, such as version control systems that track the age, programmer, and purpose of the code (e.g., control ISDN lamps, fix bug in call forwarding); static analyses, (e.g., locations where functions are called); and dynamic analyses (e.g., profiling). By means of direct manipulation and high interaction graphics, the user can manipulate this reduced representation of the code in order to find interesting patterns. Further insight is obtained by using additional windows to display the actual code. Potential applications for Seesoft include discovery, project management, code tuning, and analysis of development methodologies     

X-射线衍射物相分析的统计学方法

应用社会科学统计分析程序(SPSS)对X-射线衍射实验数据进行因子分析和聚类分析计算。结果表明在确定混合物中物相数目的同时,能够分离出每一物相的独立衍射线,为混合物的X-射线衍射物相定性分析提供了可靠的依据。     

X-射线衍射物相分析的统计学方法

应用社会科学统计分析程序（SPSS）对X-射线衍射实验数据进行因子分析和聚类分析计算。结果表明在确定混合物中物相数目的同时，能够分离出每一物相的独立衍射线，为混合物的X-射线衍射物相定性分析提供了可靠的依据。     

Inference for Weibull distribution under generalized order statistics

Based on generalized order statistics from Weibull distribution the approach of Bayesian and non-Bayesian estimation are discussed. We present a simple and efficient simulational algorithm for generating a generalized order statistics sample from any continuous distribution. Specializations to Bayesian and non-Bayesian estimators, some lifetime parameters and confidence intervals of progressive II censoring and record values are obtained and compared with the existing results. Two examples are given to illustrate the proposed estimators and the simulation algorithm.     

基于第二类统计量的K分布参数估计

为了高效估计出K分布的参数,提出了对数累积量参数估计方法。基于第二类统计量,先对K分布的概率密度函数进行Mellin变换,从而获得K分布的第二类第一特征函数;然后对第二类第一特征函数进行对数变换,由此获得K分布的第二类第二特征函数;最后对第二类第二特征函数求导数,进而获得K分布的前两阶对数累积量,由此可以估计K分布的参数。与传统的最大似然估计方法相比,K分布的对数累积量估计具有解析的表达式,易于计算。Monte Carlo仿真表明,基于第二类统计量的K分布对数累积量估计可获得较高的估计精度。     

Convergence analysis of SART: optimization and statistics

Simultaneous algebraic reconstruction technique (SART) [A. Andersen, Algebraic reconstruction in CT from limited views, IEEE Trans. Med. Imaging 8 (1989), pp. 50–55; A. Andersen and A. Kak, Simultaneous algebraic reconstruction technique (SART): A superior implementation of the ART algorithm, Ultrason. Imaging 6 (1984), pp. 81–94] is an iterative method for solving inverse problems of form Ax(+n)=b. These kinds of problems arise, for example, in computed tomography (CT) reconstruction, in which case A is obtained from the discrete Radon transform. In this paper, we provide several methods for derivation of SART and connections between SART and other methods. Using these connections, we also prove the convergence of SART in different ways. These approaches are from optimization and statistical points of view and can be applied to other Landweber-like schemes such as Cimmino's algorithm and component averaging. Furthermore, the noisy case is considered and the error estimation is given. Several numerical experiments for CT reconstruction are provided to demonstrate the convergence results in practice.     

氨气泄漏事故的统计及后果分析

统计近10年的氨气事故,并分析事故造成的损失。表明连续点源泄漏、扩散为高频事故类型。比较分析氨气泄漏及扩散模型,选高斯烟羽模型,用Visual Basic程序,编制氨气连续点源泄漏的情况下,编制模拟氨气扩散范围的扩散模拟软件。这个软件可以模拟不同破裂面积、压力、温度以及天气情况下,氨气泄漏的影响范围。本软件操作简单,输入参数少,使用方便,可以为企业或政府应急疏散提供参考。     

On the evaluation of the joint distribution of order statistics

Dunnett and Tamhane [Dunnett, C.W., Tamhane, A.C., 1992. A step-up multiple test procedure. J. Amer. Statist. Assoc. 87, 162-170.] proposed a step-up procedure for comparing k treatments with a control and showed that the step-up procedure is more powerful than its counterpart single step and step-down procedures. Since then, several modified step-up procedures have been suggested to deal with different testing environments. In order to establish those step-up procedures, it is necessary to derive approaches for evaluating the joint distribution of the order statistics. In some cases, experimenters may have difficulty in applying those step-up procedures in multiple hypothesis testing because of the computational limitation of existing algorithms in evaluating the critical values for a large number of multiple comparisons. As a result, most procedures are only workable when the design of the experiment is balanced with k≤20 or unbalanced with k≤8. In this paper, new algorithms are proposed in order to effectively compute the joint distribution of order statistics in various situations. An extensive numerical study shows that the proposed algorithms can easily handle the testing situations with a much larger k. Examples of applying the proposed algorithms to evaluate the critical values of two existing step-up procedures are also presented.     

The statistics of state-spaces

The state-space model is a general, powerful, and elegant representation of problem solving. Nevertheless, state-spaces have rarely been used to model realistic environments because conventional state-spaces are inherently deterministic, while the world is not. This paper extends the model toprobabilistic state-spaces (PSS), which elegantly capture many of the world's complexities by regarding state values as generated by random variables. These PSS models, when combined with decision analytic techniques for knowledge elicitation and encoding, should yield realistic representations. The first investigation of states based on random variables derived the expected-outcome model of two-player games, which led to some powerful results about game evaluators. Most of the work done on expected-outcome was quite general, and should extend easily beyond game-trees to arbitrary state-spaces. The second potential application domain, strategic planning for robot controllers in automated assembly plants, is currently under investigation.This research was supported in part by NSF grants IST-8513989 and IRI-8910173 and by the University of Southern California Faculty Research Initiation Fund.     

Global cloud-layer distribution statistics from 1 year CALIPSO lidar observations

In this paper, the cloud statistics and global cloud distributions are derived from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) level 2, 5 km lidar cloud-layer products between 13 June 2006 and 24 June 2007. The global cloud-layer occurrence frequency, the horizontal and the vertical distributions of cloud-occurrence frequency, the global cloud-top height statistics and their seasonal changes are given for 1 year CALIPSO observations. Opaque cloud-layer statistics are analysed for better understanding the statistics of the clouds observed using CALIPSO. Parts of the results are compared with some results from the High Resolution Infrared Radiation Sounder (HIRS) observations, the Geoscience Laser Altimeter System (GLAS) observations and the global rawinsonde observations, the Aqua MODerate Resolution Imaging Spectroradiometer (MODIS) monthly cloud-fraction data. The comparisons show that results are in agreement with other observations. Due to the primary advance from the active optical sensing, CALIPSO lidar can offer measurements of accurate, highly resolved vertical profiles of atmospheric scattering layers. It has advantages in determining the location of optically thin clouds and detecting occurrences of multiple layers. Long-term observations by CALIPSO lidar can provide valuable information for the better understanding of the climate system and global climate change.     

On the analysis of statistics of mobile visitors

This paper discusses location-based mobile services. The problem of counting mobile users (mobile phones) in a selected area is considered. The information available from the analysis of wire-less protocols (Wi-Fi, Bluetooth) is used for the calculation. The aim of the study is to construct an analog of systems of web statistics operating with real mobile subscribers (instead of data on web page visits as in web statistics). As a result, we obtain information about traffic, identification and analysis of trends in user traffic, search for the core of regular visitors, and detection of its dynamics. The paper presents algorithms for calculating network proximity and examples of use.     

考虑电网结构优化低压配电网线损计算和降损分析

针对低压配电网混合线制结构和负荷不平衡,采用电阻热效应和相分量法,提出了单电源树干式低压配电网络的各相和中性线的电流分布的计算方法,并得到了网络的线损分布.通过对一个村庄的低压配电网线损计算,得到了用户不同接线相别的网络线损,并量化分析了接线相别优化的降损效果,为降损方案的确定提供了依据.     

Approximating feeder line reliability statistics with partial data collection in assembly systems

Due to the difficulty and high cost of data collection, many feeder lines in assembly systems lack full collection of data. However, reliability statistics of feeder lines are important in throughput analysis and continuous improvement of manufacturing systems. In this paper, a simple approximation approach is presented to estimate the reliability statistics of feeder lines from the associated assembly station's collected blocking and starving information. It is shown that the approach is helpful for accurate throughput estimation and sensitivity analysis. We also show how feeder line speed can be used to improve the approximation.     

Nonparametric methods in standard statistics packages: The case of the Friedman analysis

The case of the Friedman analysis is discussed with reference to the major statistics packages. A computer program is described which is able to analyse datasets with missing observations which may be either accidental or planned as in Durbin designs — according to the generalized inverse Klotz algorithm. The program also performs asymptotically correct calculations for tied values and thus includes Cochran's Q-test as a special case. Arbitrary comparisons or contrasts can be used for very specialized hypothesis tests. All well-known measures of relevance, as for example average interrelation and Kendall's coefficient of concordance, are calculated correctly for all data types and missing data situations. As part of the validation procedure a large number of examples is evaluated and the results are compared to those in the literature or those of other major statistics packages.     

Application of 3D-wavelet statistics to video analysis

Video activity analysis is used in various video applications such as human action recognition, video retrieval, video archiving. In this paper, we propose to apply 3D wavelet transform statistics to natural video signals and employ the resulting statistical attributes for video modeling and analysis. From the 3D wavelet transform, we investigate the marginal and joint statistics as well as the Mutual Information (MI) estimates. We show that marginal histograms are approximated quite well by Generalized Gaussian Density (GGD) functions; and the MI between coefficients decreases when the activity level increases in videos. Joint statistics attributes are applied to scene activity grouping, leading to 87.3% accurate grouping of videos. Also, marginal and joint statistics features extracted from the video are used for human action classification employing Support Vector Machine (SVM) classifiers and 93.4% of the human activities are properly classified.     

配电线路绝缘包裹机器人样机研制

为了解决架空裸露导线存在的安全隐患,提出了一种用于架空裸露导线的配电线路自动绝缘包裹机器人。该机器人将机构紧凑地配合在一起,在多传感器的辅助下,能够完成在裸露导线上自主行走、包裹;采用CAN总线架构进行电机管理,PID控制算法实现各个电机的精确配合;IMU的引用实现了机器人在不同运行环境下更高效稳定的运行;机器视觉的应用实现包裹结果的实时传输与自主判断。试验表明,包裹机器人运行效果理想,具有广阔的应用前景。     

From static approximations to full-wave analysis: The analysis of planar line discontinuities

A comparison of different methods for the characterization of planar line discontinuities with emphasis on microstrip discontinuities is given, thereby describing the present state of the art in this area of microwave circuit CAD. Quasi-static equivalent circuit models, the magnetic wall waveguide model of microstrip discontinuities, full-wave analysis techniques like the orthogonal series expansion and mode matching techniques, the spectral domain analysis technique using roof-top functions, and the finite-difference time-domain technique are described briefly and compared with respect to their numerical efficiency and their capabilities.