Instance-based attribute identification in database integration

Most research on attribute identification in database integration has focused on integrating attributes using schema and summary information derived from the attribute values. No research has attempted to fully explore the use of attribute values to perform attribute identification. We propose an attribute identification method that employs schema and summary instance information as well as properties of attributes derived from their instances. Unlike other attribute identification methods that match only single attributes, our method matches attribute groups for integration. Because our attribute identification method fully explores data instances, it can identify corresponding attributes to be integrated even when schema information is misleading. Three experiments were performed to validate our attribute identification method. In the first experiment, the heuristic rules derived for attribute classification were evaluated on 119 attributes from nine public domain data sets. The second was a controlled experiment validating the robustness of the proposed attribute identification method by introducing erroneous data. The third experiment evaluated the proposed attribute identification method on five data sets extracted from online music stores. The results demonstrated the viability of the proposed method.Received: 30 August 2001, Accepted: 31 August 2002, Published online: 31 July 2003Edited by L. Raschid     

A rule-based event detection system for real-life underwater domain

Understanding and analyzing fish behaviour is a fundamental task for biologists that study marine ecosystems because the changes in animal behaviour reflect environmental conditions such as pollution and climate change. To support investigators in addressing these complex questions, underwater cameras have been recently used. They can continuously monitor marine life while having almost no influence on the environment under observation, which is not the case with observations made by divers for instance. However, the huge quantity of recorded data make the manual video analysis practically impossible. Thus machine vision approaches are needed to distill the information to be investigated. In this paper, we propose an automatic event detection system able to identify solitary and pairing behaviours of the most common fish species of the Taiwanese coral reef. More specifically, the proposed system employs robust low-level processing modules for fish detection, tracking and recognition that extract the raw data used in the event detection process. Then each fish trajectory is modeled and classified using hidden Markov models. The events of interest are detected by integrating end-user rules, specified through an ad hoc user interface, and the analysis of fish trajectories. The system was tested on 499 events of interest, divided into solitary and pairing events for each fish species. It achieved an average accuracy of 0.105, expressed in terms of normalized detection cost. The obtained results are promising, especially given the difficulties occurring in underwater environments. And moreover, it allows marine biologists to speed up the behaviour analysis process, and to reliably carry on their investigations.     

A digital library framework for biodiversity information systems

Biodiversity Information Systems (BISs) involve all kinds of heterogeneous data, which include ecological and geographical features. However, available information systems offer very limited support for managing these kinds of data in an integrated fashion. Furthermore, such systems do not fully support image content (e.g., photos of landscapes or living organisms) management, a requirement of many BIS end-users. In order to meet their needs, these users—e.g., biologists, environmental experts—often have to alternate between separate biodiversity and image information systems to combine information extracted from them. This hampers the addition of new data sources, as well as cooperation among scientists. The approach provided in this paper to meet these issues is based on taking advantage of advances in digital library innovations to integrate networked collections of heterogeneous data. It focuses on creating the basis for a next-generation BIS, combining new techniques of content-based image retrieval and database query processing mechanisms. This paper shows the use of this component-based architecture to support the creation of two tailored BIS systems dealing with fish specimen identification using search techniques. Experimental results suggest that this new approach improves the effectiveness of the fish identification process, when compared to the traditional key-based method.     

Web服务在学生信息管理系统中的应用

论述了基于Web架构,采用ASP技术设计与开发学生信息管理系统的实现方案;提出了用户管理、学生信息管理、成绩管理的设计方法,并对系统的运行环境进行了IIS安全管理设置;对储存到数据库中的用户信息进行加密。采用ADO技术访问OLEDB直接连接的数据库,使数据访问过程简单,访问效率高,从而使整个信息管理系统始终能够高效、稳定地运行和应对比较大的访问流量。     

基于B／S的学生信息管理系统研究

学生信息管理系统采用B／S三层体系结构,ASP＋IIS＋SQL Server模式,此模式将明显地把显示和逻辑分离,使代码容易管理,中间层使用数据库连接池技术加快了与数据库服务器之间的数据处理速度,同时加快对客户端响应速度。     

Web服务在学生信息管理系统中的应用

论述了基于Web架构,采用ASP技术设计与开发学生信息管理系统的实现方案;提出了用户管理、学生信息管理、成绩管理的设计方法,并对系统的运行环境进行了IIS安全管理设置;对储存到数据库中的用户信息进行加密。采用ADO技术访问OLEDB直接连接的数据库,使数据访问过程简单,访问效率高,从而使整个信息管理系统始终能够高效、稳定地运行和应对比较大的访问流量。     

Web服务在学生信息管理系统中的应用

论述了基于Web架构,采用ASP技术设计与开发学生信息管理系统的实现方案。提出了用户管理、学生信息管理、成绩管理的设计方法,并对系统的运行环境进行了IIS安全管理设置,对储存到数据库中的用户信息进行加密,采用ADO技术访问OLE DB直接连接的数据库,使数据访问过程简单,访问效率高,从而使整个信息管理系统始终能够高效、稳定的运行和应对比较大的访问流量。     

基于Web的种子植物分科检索系统的设计与实现

结合Web和数据库技术,以种子植物(科级)的形态特征建库,使用二叉式检索原理实现在Internet/Intranet上进行种子植物分类信息的查询与未知种类的鉴定,这对综合开发和合理利用种子植物资源具有指导意义.重点介绍了系统的总体结构、特征库和二叉式检索的建造,并给出了系统的运行实例.     

基于Web的种子植物分科检索系统的设计与实现*

结合Web和数据库技术,以种子植物（科级）的形态特征建库,使用二叉式检索原理实现在Internet/Intranet上进行种子植物分类信息的查询与未知种类的鉴定,这对综合开发和合理利用种子植物资源具有指导意义。重点介绍了系统的总体结构、特征库和二叉式检索的建造,并给出了系统的运行实例。     

Mining for Attribute Definitions in a Distributed Two-Layered DB System

Empirical equations are an important class of regularities that can be discovered in databases. We concentrate on the role of equations as definitions of attribute values. Such definitions can be used in many ways in a single database and for transfer of knowledge between databases. We present a quest for equations that can be used as definitions of an attribute in a given database. That quest triggers a discovery mechanism that specializes in searching recursively a system of databases and returns a set of partial definitions. We introduce the notion of shared operational semantics. It is founded on an equation-based system of partial definitions and it gives necessary foundations for designing local query answering systems in a distributed two-layered information system (D²LIS). The knowledge exchange between two sites of D²LIS may only improve an equation-based system of partial definitions at each of these sites. At the same time the shared operational semantics will better interpret user queries. Operational semantics augments the earlier developed semantics for rules used as attribute definitions. To put the shared operational semantics on a firm theoretical foundation we give a formal interpretation of queries which justifies empirical equations in their definitional role.     

Telme: a personalized, context-aware communication support system

True global communication will require more than just language translation technologies. To fully understand each other, people also need context-specific information. The authors have developed Telme, a support system that gives users real-time information to help bridge the knowledge and experience gap. The authors explain the Telme framework for wearable computers connected to a central knowledge base server. The server controls a background knowledge database and downloads data on user request.     

Searching with numbers

A large fraction of the useful Web is comprised of specification documents that largely consist of (attribute name, numeric value) pairs embedded in text. Examples include product information, classified advertisements, resumes, etc. The approach taken in the past to search these documents by first establishing correspondences between values and their names has achieved limited success because of the difficulty of extracting this information from free text. We propose a new approach that does not require this correspondence to be accurately established. Provided the data has "low reflectivity", we can do effective search even if the values in the data have not been assigned attribute names and the user has omitted attribute names in the query. We give algorithms and indexing structures for implementing the search. We also show how hints (i.e., imprecise, partial correspondences) from automatic data extraction techniques can be incorporated into our approach for better accuracy on high reflectivity data sets. Finally, we validate our approach by showing that we get high precision in our answers on real data sets from a variety of domains.     

基于模式的XML文档关系数据库存储研究

在XML文档中可以自定义元素标签,不同XML的应用名称同名的几率非常大.命名空间的使用可以区分来自不同XML文档应用的具有相同名称的元素和属性,避免元素和属性的同名冲突.命名空间在XML文档中是一类非常重要的信息,详细介绍XML文档在映射到关系数据库时对命名空间信息的提取映射.     

证据理论与熵值融合的知识约简新方法

求解决策表的最小约简已被证明是NP-hard问题,在粗糙集和证据理论的基础上提出了一种知识约简的启发式算法。利用粗糙集等价划分的概念给出属性的信息熵,定义每个属性的熵值重要性并由此确定知识的核。引入二分mass函数对每个属性建立一个证据函数,证据融合得到每个属性的证据重要性。以核为起点,以证据重要性为启发,依次加入属性直至满足约简条件。实例表明,该方法能够快速找到核和相对约简,并且该约简运用到分类上正确率也是较高的。     

区间值信息系统在双精度容差关系下的约简

为了处理一般的区间值信息系统,给出了基于相离度的相似度定义,提出了基于相似度和相似率的双精度容差关系,讨论了在双精度容差关系下区间值信息系统的属性约简与判定,并给出了一种新的基于二进制辨识矩阵的属性约简算法,同时还分别讨论了相似度和相似率对区间值信息系统的属性约简的影响。通过实例分析说明了属性约简的具体操作方法和算法的有效可行性。     

Supporting user views

Any emerging standard for object-oriented database systems must include a rich view support mechanism. A user view is a customized window into an application domain. It may be thought of as a simplifying abstraction which hides information that is not accessible to, needed or wanted by a particular user. Because they limit the information available from a given perspective, most views allow read-only access to a database. In this paper it is asserted that by generalizing object identity to include attributes and views - many view updates are made possible. An extended object structure and several categories of view transformation are also presented which allow all user views to be modeled within a single polymorphic database schema.     

An information retrieval approach for approximate queries

With the growing availability of online information systems, a need for user interfaces that are flexible and easy to use has arisen. For such type of systems, an interface that allows the formulation of approximate queries can be of great utility since these allow the user to quickly explore the database contents even when he is unaware of the exact values of the database instances. Our work focuses on this problem, presenting a new model for ranking approximate answers and a new algorithm to compute the semantic similarity between attribute values, based on information retrieval techniques. To demonstrate the utility and usefulness of the approach, we perform a series of usability tests. The results suggest that our approach allows the retrieval of more relevant answers with less effort by the user.