Parallel OLAP with the Sidera server

Online Analytical Processing (OLAP) has become a primary component of today’s pervasive Decision Support systems. As the underlying databases grow into the multi-terabyte range, however, single CPU OLAP servers are being stretched beyond their limits. In this paper, we present a comprehensive model for a fully parallelized OLAP server. Our multi-node platform actually consists of a series of largely independent sibling servers that are “glued” together with a lightweight MPI-based Parallel Service Interface (PSI). Physically, we target the commodity-oriented, “shared nothing” Linux cluster, an architecture that provides an extremely cost effective alternative to the “shared everything” commercial platforms often used in high-end database environments. Experimental results demonstrate both the viability and robustness of the design.     

About regression-kriging: From equations to case studies

This paper discusses the characteristics of regression-kriging (RK), its strengths and limitations, and illustrates these with a simple example and three case studies. RK is a spatial interpolation technique that combines a regression of the dependent variable on auxiliary variables (such as land surface parameters, remote sensing imagery and thematic maps) with simple kriging of the regression residuals. It is mathematically equivalent to the interpolation method variously called “Universal Kriging” (UK) and “Kriging with External Drift” (KED), where auxiliary predictors are used directly to solve the kriging weights. The advantage of RK is the ability to extend the method to a broader range of regression techniques and to allow separate interpretation of the two interpolated components. Data processing and interpretation of results are illustrated with three case studies covering the national territory of Croatia. The case studies use land surface parameters derived from combined Shuttle Radar Topography Mission and contour-based digital elevation models and multitemporal-enhanced vegetation indices derived from the MODIS imagery as auxiliary predictors. These are used to improve mapping of two continuous variables (soil organic matter content and mean annual land surface temperature) and one binary variable (presence of yew). In the case of mapping temperature, a physical model is used to estimate values of temperature at unvisited locations and RK is then used to calibrate the model with ground observations. The discussion addresses pragmatic issues: implementation of RK in existing software packages, comparison of RK with alternative interpolation techniques, and practical limitations to using RK. The most serious constraint to wider use of RK is that the analyst must carry out various steps in different software environments, both statistical and GIS.     

Incremental Evaluators for Remote Attribute Grammars

Remote attribute grammars use objects with separately defined fields to induce direct non-local dependencies in attribute grammars. Fields of an object may be read remotely from where it is created, and special “collection” fields may be written remotely as well. Building on earlier work which shows that remote attribute grammars can be scheduled statically, this paper shows how they may be implemented incrementally. The static schedule is used to ensure an object's fields are defined before they are read and that we never re-evaluate an attribute multiple times per edit-cycle. Dynamic dependencies are used to mark remote use sites as affected when a field is changed. The result is an efficient and practical incremental evaluation.     

遥感地学分析的智能化研究

遥感地学分析是建立在地学规律基础上的遥感信息处理和分析模型,是结合物理手段、数学 方法和地学分析等综合性应用技术和理论,通过对遥感信息的处理和分析,获得能反映地球区域分 异规律和地学发展过程的有效信息的理论方法。通过回顾遥感地学分析的发展历史,认为智能化是 遥感地学分析的一个重要发展方向,同时提出开展智能化遥感地学分析研究需要解决的几个关键 问题,最后提出了“遥感地学智能图解”的概念。     

Multidimensional visualisation for process historical data analysis: a comparative study with multivariate statistical process control

This paper describes a comparative study of a multidimensional visualisation technique and multivariate statistical process control (MSPC) for process historical data analysis. The visualisation technique uses parallel coordinates which visualise multidimensional data using two dimensional presentations and allow identification of clusters and outliers, therefore, can be used to detect abnormal events. The study is based on a database covering 527 days of operation of an industrial wastewater treatment plant. It was found that both the visualisation technique and MSPC based on T² chart captured the same 17 days as “clearly abnormal” and another eight days as “likely abnormal”. Pattern recognition using K-means clustering was also applied to the same data in literature and was found to have identified 14 out of the 17 “clearly abnormal” days.     

遥感产品真实性检验靶场构建方法初步研究

观测试验是遥感产品真实性检验的基础,通过观测试验获取的像元尺度参量真值,能确定遥感产品质量,增强其在应用领域的价值。在遥感产品真实性检验理论和方法基础上,探索构建遥感产品真实性检验试验观测靶场构建的框架,针对不同分辨率遥感产品,提出建立特征均匀靶场和非特征均匀靶场的构思;并以中国科学院怀来遥感综合试验站为例,分析了构建两种靶场的可行性,概述了目前靶场构建的进展,分析了改进的方向。以此为后期遥感产品真实性检验的观测试验提供一种思路。     

Performance analysis of GAME: A generic automated marking environment

This paper describes the Generic Automated Marking Environment (GAME) and provides a detailed analysis of its performance in assessing student programming projects and exercises. GAME has been designed to automatically assess programming assignments written in a variety of languages based on the “structure” of the source code and the correctness of the program’s output. Currently, the system is able to mark programs written in Java, C++ and the C language. To use the system, instructors are required to provide a simple “marking schema” for each given assessment item, which includes pertinent information such as the location of files and the model solution. In this research, GAME has been tested on a number of student programming exercises and assignments and its performance has been compared against that of a human marker. An in-depth statistical analysis of the comparison is presented, providing encouraging results and directions for employing GAME as a tool for teaching and learning.     

基于IP广播的计算机远程唤醒机制及其实现

通过远程唤醒使远程主机自动加电启动,进而利用远程控制软件可对远程主机进行有效控制。基于IP广播的计算机远程唤醒机制,采用WinSock实现了计算机的远程唤醒、远程关机和重新启动,从而为远程控制计算机提供有力支持。     

学习对象元数据在远程教育有效利用研究

随着远程教育的不断发展,如何进行信息资源共享已经成远程教育发展中迫切需要解决的重要任务.在对远程教育中学习对象元数据应用和关键技术分析的基础上,研究在远程教育信息资源共享中如何有效利用学习对象元数据.     

Analysis of an infinite buffer system with random server interruptions

An infinite buffer with general arrival process, synchronous transmission, one single output channel and random server interruptions is considered.As opposed to previous analyses the interruption process of the output line is kept rather general, i.e. the server is assumed to be in one of two states, “available” or “blocked”, where the sojourn time of the blocked state is arbitrarily distributed and the sojourn time of the available state has a density function which is a mixture of a finite number of geometric densities. For this general case the probability generating function of the buffer occupancy at various time instants is derived.The results of the study are applied to the case where the server interruptions are due to the presence of speech at the input of the transmission channel of an integrated voice-data system. Some considerable deviations from earlier results are found.     

Stabilization of Nonlinear Dynamic Systems Using the System State Estimates Made by the Asymptotic Observer

Consideration was given to asymptotic stabilization of the equilibria of nonlinear dynamic systems using the dynamic output feedbacks, that is, the feedbacks in the estimate of system state made by the asymptotic observer. Presented were the basic methods of constructing the asymptotic observers for the nonlinear dynamic systems with control and the approaches to system stabilization using the system state estimate made by the observer.__________Translated from Avtomatika i Telemekhanika, No. 7, 2005, pp. 3–42.Original Russian Text Copyright © 2005 by Golubev, Krishchenko, Tkachev.This work was supported by the Russian Foundation for Basic Research, project no. 05-01-00840, Grant for State Support of the Leading Scientific Schools, project no. NSh-2094.2003.1, and project no. UR.03.01.141 of Section 1.2 “Russian Universities” of the Subprogram “Basic Research” of the Departmental Scientific Program “Development of the Scientific Potentialities of the Higher School” of the Federal Education Agency of the Russian Federation.     

Implementation of higher-order asymptotics to S-plus

Higher-order asymptotics is an active area of development in theoretical statistics. However, most existing work in higher-order asymptotics is directed to the theoretical aspects. This paper attempts to incorporate higher-order inference procedures to S-plus, a widely used software in statistics. Algorithm is developed in the settings of generalized linear models and nonlinear regression models. The proposed algorithm generalizes the standard S-plus functions “glim” and “nls” in the sense that both the first-order and higher-order p-values are provided, and its manipulation is straightforward.     

《遥感技术与应用》30年论文发表趋势

自《遥感技术与应用》1986年创刊以来,走过了30年的历程,现已成为国内遥感研究成果的主要载体之一。利用现有的CSCD和CNKI数据库,从文献计量角度分析《遥感技术与应用》30年的发文趋势。结果表明:30a来,《遥感技术与应用》的论文发表数量总体呈快速增长趋势;相关研究机构主要集中在西北和北京两地;Landsat和MODIS是研究最多的两种遥感数据;土地利用是关注最多的遥感应用研究。引文分析的结果表明《遥感技术与应用》刊载的论文被CSCD和SCI引用频次和期刊影响因子不断提高,进一步说明了学界对遥感技术相关问题的关注程度不断加强。此外,计算机技术、数据科学、大数据等技术的发展促进了遥感科学的发展;另一方面,自然灾害、大气环境问题、粮食安全和可持续发展问题以及"Future Earth"的战略部署,都需要依托遥感技术获取更为可靠的数据源、构建更加系统的数据平台及面向更加智能的决策平台。     

The MMPI is less sensitive to the automated testing format than it is to repeated testing: Item and scale effects

This study examines the magnitude of the effects of the computerized assessment format on MMPI responses, and discusses methodological considerations important in evaluating the sensitivity of personality inventories to different administration formats. Previous research suggested that subjects were more frank in impersonal assessment situations, and that computerized administration increases the use of the “Cannot Say” response. Although tending to minimize the effects of automated testing, the study designs and statistical procedures employed to date have been relatively insensitive to format differences. The present research analyzes item-level effects of computerized test administration using a crossover ANOVA design including the effects of order of administration, format of administration, and repeated testing. One hundred and fifty undergraduate subjects took a paper and pencil and computer-administered MMPI a week apart, in two different orders. Overall, the effects of the automated testing format are small compared with the effects of repeated testing when subjects; use of the “Cannot Say” response is controlled. Observed format differences are not in the direction of “frankness” or “candor” in the computer administration format. An index of each subject's sensitivity to computerized administration is computed and used to evaluate characteristics associated with shifting responses in the computerized testing format.     

Statistical pattern recognition in remote sensing

Remote sensing with sensors mounted on satellites or aircrafts is much needed for resource management, environmental monitoring, disaster response, and homeland defense. Remote sensing data considered include those from multispectral, hyperspectral, radar, optical, and infrared sensors. Classification is often one of the major tasks in information processing. For example, we need to identify vegetations, waterways, and man-made structures from remote sensing of earth. The large amount of data available makes remote sensing data uniquely suitable for statistical pattern recognition. This paper will address several issues on statistical pattern recognition that are related to information processing in remote sensing. Though the paper is largely tutorial in nature, some specific issues considered are image models for characterization of contextual information, neural networks for image classification, and the performance measures.Either to supplement the capability of sensors or to effectively utilize the enormous amount of sensor data, many advances in statistical pattern recognition can be very useful in machine recognition of the data. The potentials and opportunities of using statistical pattern recognition in remote sensing are indeed unlimited.     

A “mixed” small gain and passivity theorem in the frequency domain

We show that the negative feedback interconnection of two causal, stable, linear time-invariant systems, with a “mixed” small gain and passivity property, is guaranteed to be finite-gain stable. This “mixed” small gain and passivity property refers to the characteristic that, at a particular frequency, systems in the feedback interconnection are either both “input and output strictly passive”; or both have “gain less than one”; or are both “input and output strictly passive” and simultaneously both have “gain less than one”. The “mixed” small gain and passivity property is described mathematically using the notion of dissipativity of systems, and finite-gain stability of the interconnection is proven via a stability result for dissipative interconnected systems.     

Adaptation of maximum entropy capitalizer: Little data can help a lot

A novel technique for maximum “a posteriori” (MAP) adaptation of maximum entropy (MaxEnt) and maximum entropy Markov models (MEMM) is presented.The technique is applied to the problem of automatically capitalizing uniformly cased text. Automatic capitalization is a practically relevant problem: speech recognition output needs to be capitalized; also, modern word processors perform capitalization among other text proofing algorithms such as spelling correction and grammar checking. Capitalization can be also used as a preprocessing step in named entity extraction or machine translation.A “background” capitalizer trained on 20 M words of Wall Street Journal (WSJ) text from 1987 is adapted to two Broadcast News (BN) test sets – one containing ABC Primetime Live text and the other NPR Morning News/CNN Morning Edition text – from 1996.The “in-domain” performance of the WSJ capitalizer is 45% better relative to the 1-gram baseline, when evaluated on a test set drawn from WSJ 1994. When evaluating on the mismatched “out-of-domain” test data, the 1-gram baseline is outperformed by 60% relative; the improvement brought by the adaptation technique using a very small amount of matched BN data – 25–70k words – is about 20–25% relative. Overall, automatic capitalization error rate of 1.4% is achieved on BN data.The performance gain obtained by employing our adaptation technique using a tiny amount of out-of-domain training data on top of the background data is striking: as little as 0.14 M words of in-domain data brings more improvement than using 10 times more background training data (from 2 M words to 20 M words).     

Structural Analysis of the Time Data Series

Consideration was given to different methods of structural analysis of the data series which are intended for expeditious determination of the “special points”—the instants of changes in trends. The data about different physical units such as technical, market, and other objects feature great dynamic variety in terms of their trends, local structural characteristics, and sliding statistical characteristics. Expeditious recognition of the instants of changes in the realization characteristics enables one to make timely decisions about normal operation of the objects under consideration. A multivariant approach to structural analysis of data realizations was proposed to enhance the reliability of determining the instants of occurrence of special points. Particular examples of multivariant structural analysis were presented.__________Translated from Avtomatika i Telemekhanika, No. 6, 2005, pp. 161–169.Original Russian Text Copyright © 2005 by Ageev, Burkov, Zinchenko, Kiseleva.     

The development of generic definitions of hyperslice packages in Hyper/J

In this paper we investigate the notion of reusability of aspect definitions. We discuss the development of generic aspects in Hyper/J and compare it with the AspectJ approach. In doing that, we follow the design principle of “developing with hyperslice packages” and we show that hyperspace structure, concern mapping, hyperslice definitions and merging stategies exhibit well-defined patterns. An approach to constructing and merging generic aspects with base core concerns in Hyper/J is presented.