Modeling and Management of Fuzzy Information in Multimedia Database Applications

In this paper, we firstly present a conceptual data model for multimedia database applications based on ExIFO₂ model. The ExIFO₂ data model is chosen as the conceptual model since it handles complex objects along with their uncertain and imprecise properties. We enhanced this conceptual model in order to meet the multimedia data requirements. In addition to uncertain and imprecise information, we present a way of handling relationships among objects of multimedia database applications. Events that might be extracted from video or audio are also considered in this study. Secondly, the conceptual model is mapped to a logical model, which the fuzzy object-oriented data (FOOD) model is chosen, for storing and manipulating the multimedia objects. This mapping is done in a way that it preserves most of the information represented at the conceptual level. Finally, in this study videos of football (soccer) games is selected as the multimedia database application to show how we handle crisp and fuzzy querying and retrieval of fuzzy and crisp data from the database. A program has been developed to draw ExIFO₂ schemas and to map the schema to FOOD code automatically.     

Systems Dynamics-Based Modeling of Data Warehouse Quality

ABSTRACT

Data warehouses (DW) are a key component of business intelligence and decision-making. In this paper, we present an approach that combines Grounded Theory and System Dynamics to develop causal loop diagrams/models for data warehouse quality and processes. We used the top 51 data warehousing academic papers to arrive at concepts and critical success factors. A simple data warehouse quality causal model and a Data Warehouse Project Initialization Loop Analysis, Data Source Availability & Monitoring Loop Analysis and Data Model Quality and DBMS Quality Analysis models were developed. Visualization of the cause-effect loops and how data warehouse variables are interrelated provide a clear understanding of DW process. Key findings include data quality and data model quality that are more important than DBMS quality for ensuring data warehouse quality, and the number of data entry errors and the level of data complexity can be major detriments to DW quality.     

一种评估数据仓库设计质量的方法

数据仓库（Data Warehouse,DW）是支持决策管理过程的、面向主题的、集成的、随时间而变的、持久的数据集合,它集成了源数据库（Database,DB）和其他平面文件系统的相关数据,以支持决策管理活动。数据仓库结构是一个多维模型,主要分星形、雪花星和星座形三种。有别于传统关系型数据库的设计,数据库仓库的设计往往以数据作为驱动,其设计的好坏,直接影响了数据仓库系统的建设与应用。文中提出了一种评估数据仓库设计质量的定量分析方法,主要是量化了和数据仓库有血缘关系的数据源的相关质量指标,就是通过分析所选取的表和属性两方面的数据质量（Data Quality,DQ）指标,最终联合这些指标以计算数据仓库设计质量的评估值。其中,分析数据源相关质量指标的过程,也可以支持数据库仓库的设计。     

土地利用现状数据建库数据质量评价与控制研究

在江苏省部分县市1∶1万土地利用现状调查数据建库基础上,研究了建库过程中影响数据质量的主要因素和因子,给出了影响数据质量的主要因素与因子的权重。以模糊数学原理和方法为基础,建立了数据质量综合评价模型,同时利用SPC方法初步研究了数据建库过程中数据质量的控制。     

通用数据质量评估模型及本体实现

随着数据科学技术在各个领域的深度应用,作为企业重要资产的数据越发表现出它的价值性与重要性.绝大多数企业结合行业特点开发了数据质量检测系统来解决自身数据质量问题.这些系统的评估模型各有特点,对于数据质量维度的定义也是各有千秋.试图将这些模型与数据质量维度以一种通用的形式来定义,旨在成为企业研发数据质量评估系统的标准.通过分析国内外学者在该研究领域取得的成果并结合常年研发数据质量检测与评估系统的经验,首先,提出了一个通用的数据质量检测与评估的数学模型;接着,以此模型为基础,采用本体技术定义了从该通用的数据质量评估数学模型到本体模型映射的转换规则;随后,考虑到多数数据存储在关系数据库中,因此以关系数据模型为例,依据所提出的数学模型和转换规则实现了对数据质量评估本体的抽取与构建,该模型实现了复杂质量规则的定义,具有规范性,实现了对不同来源、不同格式的数据质量进行检测与评估;最后,结合中国石油的油田开发数据质量评估项目进行了系统的实现,验证所提出模型的正确性、科学性、合理性以及可扩充性等.由于所提出的数据质量检测与评估模型与领域无关,所以它具有通用性.     

Checking enforcement of integrity constraints in database applications based on code patterns

Integrity constraints (including key, referential and domain constraints) are unique features of database applications. Integrity constraints are crucial for ensuring accuracy and consistency of data in a database. It is important to perform integrity constraint enforcement (ICE) at the application level to reduce the risk of database corruption. We have conducted an empirical analysis of open-source PHP database applications and found that ICE does not receive enough attention in real-world programming practice. We propose an approach for automatic detection of ICE violations at the application level based on identification of code patterns. We define four patterns that characterize the structures of code implementing integrity constraint enforcement. Violations of these patterns indicate the missing of integrity constraint enforcement. Our work contributes to quality improvement of database applications. Our work also demonstrates that it is feasible to effectively identify bugs or problematic code by mining code patterns in a specific domain/application area.     

一种通用的数据质量评估控制元数据模型

为解决传统数据质量评估实现方式灵活性与通用性较差的问题,通过对元数据应用与数据质量评估体系的研究,重点分析了元数据在数据质量评估过程中的作用、数据质量评估维度与评估算法;确定基础元数据、评估控制元数据与评估算法元数据,并构建元数据模型.通过实际应用证明模型具有良好的灵活性与通用性.     

海洋渔业数据库质量控制研究

为了利用可视化技术来对海洋渔业数据库进行质量控制，在综述了近年来GIS数据库质量控制的基础上，首先提出了GIS数据库质量控制的多层次概念模型；然后针对海洋渔业地理信息系统的特点，给出了海洋渔业数据库质量控制的体系结构和具体的控制方法，并在现有的元数据和数据仓库技术的基础上，提出了基于元数据的智能化控制方法原理；最后结合前人工作和国家863计划818主题的海洋渔业GIS课题研究成果，给出该质量控制的概念模型应用于海洋渔业具体的控制体系和方法。     

数据质量分析及应用

随着信息系统的广泛应用,人们在获得海量信息的同时,越来越被数据的质量问题所困扰[1]。自从数据库管理系统(DBMS)出现后,数据已不再是程序的附属品,转而成为一种独立的产品。在应用程序升级换代的过程中,数据不但贯穿始终,而且变得越来越宝贵。文中以税务行业为应用背景,从实践角度探讨了分析数据质量的若干途径。阐述了数据质量的定义;针对定义的各项标准,分别阐述采用的解决方法;最后对数据质量分析的未来发展进行了展望。     

面向对象的数据模型设计方法的研究与实现

应用程序处理的数据大部分来源于数据库,数据库中的数据与应用程序交互的数据模型接口存在差异,如何利用更适合应用的＂概念模型＂来处理数据库中的数据,简化应用程序的设计和调用,是软件设计师和数据架构师必须合作解决的问题。利用概念模型的方法将数据在存储和调用过程中的复杂问题简易化,从而为大型应用程序的数据处理提供一种方法。     

支持数据库访问的进程检查点技术研究与实现

现有的检查点技术不支持socket连接的恢复,也没有将进程恢复和数据恢复结合起来,因此不能支持含有数据库访问的应用程序.本文提出一种支持含有数据库访问的进程检查点技术.对于含有数据库访问的应用程序,在设置进程检查点之前,先设置数据库检查点,获取当前数据库的系统改变号SCN,然后生成进程检查点.当程序从进程检查点处恢复运...     

Evaluating the quality of entity relationship models

Entity Relationship (E-R) models are at the core of logical database design. This paper describes the development of a model, associated metrics and methodology for assessing the quality of an E-R model. The model was developed by investigating into the causal relationships between ontological and behavioural factors influencing data quality. The methodology describes aggregation of the scores on various metrics to calculate an overall quality score for an E-R model, and use of the model to identify problem areas if the individual quality scores on different factors do not meet organizational standards. Further possible improvement of the model and future research issues are also discussed.     

A Taxonomy of Dirty Data

Today large corporations are constructing enterprise data warehouses from disparate data sources in order to run enterprise-wide data analysis applications, including decision support systems, multidimensional online analytical applications, data mining, and customer relationship management systems. A major problem that is only beginning to be recognized is that the data in data sources are often dirty. Broadly, dirty data include missing data, wrong data, and non-standard representations of the same data. The results of analyzing a database/data warehouse of dirty data can be damaging and at best be unreliable. In this paper, a comprehensive classification of dirty data is developed for use as a framework for understanding how dirty data arise, manifest themselves, and may be cleansed to ensure proper construction of data warehouses and accurate data analysis. The impact of dirty data on data mining is also explored.     

基于时效规则的数据修复方法

数据时效性是影响数据质量的重要因素,可靠的数据时效性对数据检索的精确度、数据分析结论的可信性起到关键作用.数据时效不精确、数据过时等现象给大数据应用带来诸多问题,很大程度上影响着数据价值的发挥.对于缺失了时间戳或者时间不准确的数据,精确恢复其时间戳是困难的,但可以依据一定的规则对其时间先后顺序进行还原恢复,满足数据清洗及各类应用需求.在数据时效性应用需求分析的基础上,首先明确了属性的时效规则相关概念,对属性的时效规则等进行了形式化定义;然后提出了基于图模型的时效规则发现以及数据时序修复算法;随后,对相关算法进行了实现,并在真实数据集上对算法运行效率、修复正确率等进行了测试,分析了影响算法修复数据正确率的一些影响因素,对算法进行了较为全面的分析评价.实验结果表明,算法具有较高的执行效率和较好的时效修复效果.     

An integrated temporal data model incorporating time series concept

Most temporal data models have concentrated on describing temporal data based on versioning of objects, tuples or attributes. The concept of time series, which is often needed in temporal applications, does not fit well within these models. The goal of this paper is to propose a generalized temporal database model that integrates the modeling of both version-based and time-series based temporal data into a single conceptual framework. The concept of calendar is also integrated into our proposed model. We also discuss how a conceptual Extended-ER design in our model can be mapped to an object-oriented or relational database implementation.     

过程数据挖掘及进展

工业过程已是一个海量的数据源,需要从中提取知识以支持过程优化。分析了工业过程数据的特点,将数据挖掘的思想引入生产过程优化中,提出了工业过程数据挖掘的概念,即是一个不依赖精确的数学模型,而自动或半自动地从工业过程数据中提取有用的知识,以支持过程变量预报、过程优化及过程故障诊断的特殊数据处理过程。总结了过程数据挖掘在过程变量预报、过程监视与优化及过程故障诊断中的研究进展,得出过程数据挖掘应在算法的设计、商业软件的开发及过程数据仓库与过程数据挖掘的集成三方面开展创新工作的结论。     

An AGENDA for testing relational database applications

Database systems play an important role in nearly every modern organization, yet relatively little research effort has focused on how to test them. This paper discusses issues arising in testing database systems, presents an approach to testing database applications, and describes AGENDA, a set of tools to facilitate the use of this approach. In testing such applications, the state of the database before and after the user's operation plays an important role, along with the user's input and the system output. A framework for testing database applications is introduced. A complete tool set, based on this framework, has been prototyped. The components of this system are a parsing tool that gathers relevant information from the database schema and application, a tool that populates the database with meaningful data that satisfy database constraints, a tool that generates test cases for the application, a tool that checks the resulting database state after operations are performed by a database application, and a tool that assists the tester in checking the database application's output. The design and implementation of each component of the system are discussed. The prototype described here is limited to applications consisting of a single SQL query. Copyright © 2004 John Wiley & Sons, Ltd.     

CFD验证与确认数据库平台数据结构设计与应用

计算流体动力学（CFD,computational fluid dynamics）验证与确认数据库平台用于存储和管理精细风洞试验、飞行试验、数值计算产生的标准算例数据。针对结构复杂、维度较高且参数不固定的CFD验证与确认标准算例数据,设计一种灵活的数据结构,动态存储不同标准算例的来流状态数据与结果数据,减少数据冗余,提高数据可扩展性。基于该数据结构完成标准算例数据质检与元数据管理设计,确保数据库平台能够精准、高效的为CFD软件可信度评价或相关研究提供数据服务。应用证明,验证与确认数据库平台实现了标准算例数据的有效管理和高效应用,为国家数值风洞工程和国内相关CFD软件的验证和确认提供了有力支撑。     

A Transaction Model to Improve Data Availability in Mobile Computing

We incorporate a prewrite operation before a write operation in a mobile transaction to improve data availability. A prewrite operation does not update the state of a data object but only makes visible the future value that the data object will have after the final commit of the transaction. Once a transaction reads all the values and declares all the prewrites, it can pre-commit at mobile host (MH) (computer connected to unreliable mobile communication network). The remaining transaction's execution (writes on database) is shifted to the mobile service station (MSS) (computer connected to the reliable fixed network). Writes on database consume time and resources and are therefore shifted to MSS and delayed. This reduces wireless network traffic congestion. Since the responsibility of expensive part of the transaction's execution is shifted to the MSS, it also reduces the computing expenses at mobile host. A pre-committed transaction's prewrite values are made visible both at mobile and at fixed database servers before the final commit of the transaction. Thus, it increases data availability during frequent disconnection common in mobile computing. Since a pre-committed transaction does not abort, no undo recovery needs to be performed in our model. A mobile host needs to cache only prewrite values of the data objects which take less memory, transmission time, energy and can be transmitted over low bandwidth. We have analysed various possible schedules of running transactions concurrently both at mobile and fixed database servers. We have discussed the concurrency control algorithm for our transaction model and proved that the concurrent execution of our transaction processing model produces only serializable schedules. Our performance study shows that our model increases throughput and decreases transaction-abort-ratio in comparison to other lock based schemes. We have briefly discussed the recovery issues and implementation of our model.