改进XISS索引技术的仿真研究

研究了数据库查询优化问题,而XISS索引是XML数据库索引中支持正则路径表达式的典型代表。XISS索引对于长查询路径表达式,要产生大量中间结果,连接操作代价十分高,加大了查询的时间和空间复杂度,导致查询的效率和准确率低。为了提高XML数据库查询效率和准确率,提出一种改进的XISS索引技术。首先引入DTD模式信息,简化编码方式;然后对节点索引结构进行改进,减少中间结果的连接次数,使得查询时间与路径长度无关,提高了查询效率和准确率。最后通过实验对改进前后的XISS索引进行仿真。结果表明,改进的XISS索引缩短了建立索引的时间,加快了查询响应的速度,提高了XML数据库查询的效率和准确率。     

一种基于数据访问流的数据库索引优化方法

提出了一种基于数据访问流进行索引优化的方法,该方法通过集成业务流程模型与数据模型,抽取了流程活动中包含的数据访问操作和流程的控制结构形成数据访问流,分析了数据访问流中数据访问操作的频度,为频繁数据访问操作所对应的数据项创建索引,达到改善数据访问性能的目的。实验结果表明,该方法提高了数据查询的速度。     

基于OLAP的医疗保健数据处理设计与实现

为了有效地利用数据资源,提高决策支持的能力,需要研制相应的OLAP解决方案。详细介绍了联机分析处理的基本概念和数据分析方法。在此基础上提出了适用于医疗保健数据处理应用的设计与实现方法,构建了系统的整体结构,详细分析了各模块的功能,建立了数据模型,使用VB6．0和SQL Server等开发工具进行了系统的实现。经过对实现结果的分析,达到了最初的设计要求。     

A new modeling interface for the pen-input displays

Sketch interactions based on interpreting multiple pen markings into a 3D shape is easy to design but not to use. First of all, it is difficult for the user to memorize a complete set of pen markings for a certain 3D shape. Secondly, the system will be waiting for the user to complete the sequence of the pen markings, often causing a certain mode error. To address these problems, we present a novel, interaction framework, suitable for interpretations based on single-stroke marking on pen-input display; within this framework 3D shape modeling operations are designed to create appropriate communication protocols.     

The influence of color grouping on users’ visual search behavior and preferences

The article investigates how the various colors and color pairs used as grouping factors affect the visual search process and direct manipulation activities in the context of toolbar-like graphical panels. Red, green, and blue colors having the same perceptual distance in the CIELab space are used. The results demonstrate significant influence of the examined color-related factors on the speed and accuracy. The color preattentive property depends strongly on the grouping pattern: layouts with smaller colored areas were operated worse than panels divided into larger parts. Meaningful differences were also observed between panels with single and two colored backgrounds.     

VFP6.0查询与索引使用技巧拾零

提出中文VFP6.0查询与索引使用过程中所遇到的问题及其获得解决的有效方法和技巧。     

Optically based direct manipulation for augmented reality

Augmented reality (AR) constitutes a very powerful three-dimensional user interface for many “hands-on” application scenarios. To fully exploit the AR paradigm, the computer must not only augment the real world, but also accept feedback from it. In this paper, we present an optical approach for collecting such feedback by analyzing video sequences to track users and the objects they work with. Our system can be set up in any room after quickly placing a few known optical targets in the scene. We present two demonstration scenarios to illustrate the overall concept and potential of our approach and then discuss the research issues involved.     

数字图像处理课程的多视图模型

工科教学的一个难题是激发学生兴趣,提高其独立学习和设计能力。以数字图像处理这一课程为实施对象,提出了以理论模型为主线、以编程模型和图像处理效果可视化模型为副线的多视图教学模型,以解决该课程原有教学模式方法单一、过程枯燥等问题。采用该模型取得了较好的教学效果,实现数学理论模型和编程技术的一体化建模:学生不仅能够理解如何采用数字图像处理的基本理论进行工程应用,而且能够掌握图像处理基本编程能力。     

数据库查询中索引的应用

索引是对数据库表中一列或多列的值进行排序的一种结构。如何合理地使用索引。以及使用索引时应注意的事项．都是本文讨论的问题。并为数据库设计者提供很好的参考。     

语音信号处理技术及其应用前景分析

语音识别技术目前的技术框架主要基于模式识别,对数据的匹配性要求很高,对方言、口音以及口语的处理能力还存在很大的瓶颈,即使是标准口音,也需要用户较高的配合度。、本文介绍了语音信号处理技术的研究现状及几种常见的技术方法,并且分析探讨了语音信号处理技术的应用和发展前景。     

Internet搜索引擎索引数据库的设计与实现

Internet网络环境搜索引擎主要由三部分组成：搜索器、索引数据库和用户界面。搜索器搜索到Internet的Web页面后，将页面信息存入索引数据库，最后通过用户界面提供给用户。介绍索引数据库的组织和索引过程的实现。搜索器采用Spider，将搜索结果存入索引数据库。     

位图索引的设计与实现

文章在分析了几种现有位图索引的基础上，为国产数据库系统DM设计了分段范围编码位图索引。最后介绍了DM位图索引的建立以及查询方法。     

“数字海洋”的数据处理与应用模式研究

在分析"数字海洋"信息需求的基础上,提出了数据处理与信息服务模型."数字海洋"的数据处理与信息服务模型由数据获取、数据处理、增值信息服务组成,即数据处理模块提供基本的信息与产品及其共享服务,以及进一步进行信息处理提供增值信息服务.以海流模型应用为例分析了基于"数字海洋"的应用模式.     

可扩展工作流模型的信访业务协同处理系统

根据可定制业务流程和信息安全访问控制的需求,提出了一种可扩展动态工作流的协同处理模型。用户可以按照任务处理环节的需求以工作流子模型为核心定制任务中的活动类型和业务处理逻辑,定制各种附加子模型的业务知识与规则,并将基于角色和任务的访问控制运用于模型中,实现安全访问控制的工作流建模。利用该模型,研发了信访业务协同处理系统,介绍了系统的动态工作流管理技术、基于角色和任务的工作流访问控制与协调处理方法、以及基于任务授权控制的监控机制。三年多的应用情况证明,该系统在系统维护、协同处理、以及监控异常方面,具有应用优势。     

QAAS: quick accurate auto-scaling for streaming processing

In recent years, the demand for real-time data processing has been increasing, and various stream processing systems have emerged. When the amount of data input to the stream processing system fluctuates, the computing resources required by the stream processing job will also change. The resources used by stream processing jobs need to be adjusted according to load changes, avoiding the waste of computing resources. At present, existing works adjust stream processing jobs based on the assumption that there is a linear relationship between the operator parallelism and operator resource consumption (e.g., throughput), which makes a significant deviation when the operator parallelism increases. This paper proposes a nonlinear model to represent operator performance. We divide the operator performance into three stages, the Non-competition stage, the Non-full competition stage, and the Full competition stage. Using our proposed performance model, given the parallelism of the operator, we can accurately predict the CPU utilization and operator throughput. Evaluated with actual experiments, the prediction error of our model is below 5%. We also propose a quick accurate auto-scaling (QAAS) method that uses the operator performance model to implement the auto-scaling of the operator parallelism of the Flink job. Compared to previous work, QAAS is able to maintain stable job performance under load changes, minimizing the number of job adjustments and reducing data backlogs by 50%.     

Predicting Enhanced Vegetation Index (EVI) curves for ecosystem modeling applications

Vegetation indices derived from remote sensing data provide information about the variability in stature, growth and vigor of the vegetation across a region, and have been used to model plant processes. For example, the Enhanced Vegetation Index (EVI) provides a measure of greenness of the vegetation that can be used to predict net primary production. However, ecosystem models relying on remote sensing data for EVI or other vegetation indices are limited by the time series of the satellite data record. Our objective was to develop a statistical model to predict EVI in order to extend the time series for modeling applications. To explain the functional behavior of the seasonal EVI curves, a two-stage multiple regression fitting procedure within a semi-parametric mixed effect (SPME) model framework was used. First, a linear mixed effect (LME) model was fitted to the EVI with climate indexes, crop and irrigation information as predictor variables. Second, Penalized B-splines were used to explain the behavior of the smooth residuals, which result from a smooth model fit to the smooth EVI data curve, in order to describe the uncertainty of the EVI curve. Individual models were fit within individual Major Land Resources Areas (MLRAs). Predicted seasonal EVI, derived from our regression equations, showed a strong agreement with the observed EVI and was able to capture the site by site and year by year variation in the EVI curve. Out-of-sample prediction produced excellent results for a majority of the sites, except for sites without clear seasonal patterns, which may have resulted from cloud contamination and/or snow cover. Therefore, given the appropriate climate, crop, and irrigation information, the proposed approach can be used to predict seasonal EVI curves for extending the time series into the past and future.     

Acquisition of manipulative grounded symbols for integration of symbolic processing and stimulus-reaction type parallel processing

The architecture constructed with two types of processing, logical symbol processing and stimulus-reaction type parallel processing, seems promising for intelligent systems. Since symbol processing is constructed by a top-down approach and stimulus-reaction type processing is built up by a bottom-up approach, a discrepancy, which is called the 'symbol grounding problem', takes place. This paper presents a framework for integration of symbol processing and stimulus-reaction type processing from the viewpoint of solving the symbol grounding problem. In this framework designers or users use the conventional heuristic symbols and the systems use the self-organized symbols based on the characteristics/environment of the systems themselves. Translation from one to another produces the fusion of those two symbols. The self-organized symbols are grounded and manipulative. Navigation of an autonomous robot is simulated. Acquisition of manipulative grounded symbols with the proposed framework is demonstrated. Since the constructed robot is equipped only with a stimulus-reaction type controller, it has a robustness against noise and temporary geometrical changes.     

基于分词索引的全文检索技术介绍

研究基于分词的全文检索技术.通过对不同的检索技术进行比较,证明分词索引的优越性.同时读者可以认识到各种检索技术的长短,以根据要求进行选择.     

Direct manipulation of graph-based decision models

This paper builds on a long tradition in operations research and systems analysis: building models by drawing pictures. While pictorial representations are certainly useful as a communication medium, we focus on the learnability of modeling applications through graphical interfaces. Using the combined perspectives of direct perception (especially affordances) and direct manipulation, we focus on the dynamics of model building and model manipulation. The GX Shell is a DSS interface generator for direct manipulation of graph-based decision models, which are processed either by routines coded in Prolog or by external solvers.