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1.
We propose a framework for database querying providing the user with several interaction paradigms based on different (i.e., form-based, diagrammatic, iconic, and hybrid) visual representations of the database. A unified model, namely the Graph Model, is used as the common underlying model, in terms of which databases expressed in the most common data models can be easily converted. Graph Model databases can be queried by means of the multiparadigmatic interface. The semantics of the query operations is formally defined in terms of the Graphical Primitives. Such a formal approach enables the query manager to maintain the same query consistently in any representation. In the proposed multiparadigmatic environment, the user can switch from one interaction paradigm to another during query formulation, so that the most suitable query representation can be found.  相似文献   

2.
A system to query databases using diagrams as a standard user interface is proposed. The system, called Query by Diagram* (QBD*), makes use of a conceptual data model, a query language on this model, and a graphical user interface. The conceptual model is the entity-relationship model. The query language, whose expressive power allows recursive queries, supports visual interaction. The main characteristics of the interface are ease of use and the availability of a rich set of primitives for schema selection and query formulation. The expressive power of QBD* and G+, which are the only languages allowing recursive queries to be expressed graphically are compared  相似文献   

3.
The object-oriented paradigm has a number of widely recognised strengths when applied to data management, but the increased complexity of actual systems compared with their relational predecessors often means that such databases are less readily accessible to nonprogrammers than relational systems. A number of proposals have been made for textual, form-based and graph-based query interfaces to object-oriented databases, but it is clear that a single approach cannot be considered to be the best, given the wide range of potential user groups, application domains and tasks. The paper presents a query interface to an object-oriented database which supports alternative user-level query paradigms in a fully integrated environment, thereby enabling different categories of user to select a preferred interface paradigm from a list of options. Furthermore, the interface enables users to examine queries written in one query interface using any of the other interface paradigms, which is useful for sharing queries in the multi-paradigm context, and for helping users familiar with one approach to learn another. The system has been prototyped using the ADAM object-oriented database system, and an experimental comparison of different interaction modes has been conducted.  相似文献   

4.
We describe two scenarios of user tasks in which access to multimedia data plays a significant role. Because current multimedia databases cannot support these tasks, we introduce three new requirements on multimedia databases: multimedia objects should be active objects, querying is an interaction process, and query processing uses multiple representations. We discuss three techniques to handle multimedia objects as active objects. Also, we introduce a promising database architecture to meet the new user requirements. Agents within the database handle objects' representations, and a search engine on top of a conventional database handles relevance feedback and multiple representations.  相似文献   

5.
High user interaction capability of mobile devices can help improve the accuracy of mobile visual search systems. At query time, it is possible to capture multiple views of an object from different viewing angles and at different scales with the mobile device camera to obtain richer information about the object compared to a single view and hence return more accurate results. Motivated by this, we propose a new multi-view visual query model on multi-view object image databases for mobile visual search. Multi-view images of objects acquired by the mobile clients are processed and local features are sent to a server, which combines the query image representations with early/late fusion methods and returns the query results. We performed a comprehensive analysis of early and late fusion approaches using various similarity functions, on an existing single view and a new multi-view object image database. The experimental results show that multi-view search provides significantly better retrieval accuracy compared to traditional single view search.  相似文献   

6.
We develop a formal logical foundation for secure deductive databases. This logical foundation is based on an extended logic involving several modal operators. We develop two models of interaction between the user and the database called “yes-no” dialogs, and “yes-no-don't know” dialogs. Both dialog frameworks allow the database to lie to the user. We develop an algorithm for answering queries using yes-no dialogs and prove that secure query processing using yes-no dialogs is NP-complete. Consequently, the degree of computational intractability of query processing with yes-no dialogs is no worse than for ordinary databases. Furthermore, the algorithm is maximally cooperative to user in the sense that lying is resorted to only when absolutely necessary. For Horn databases, we show that secure query processing can be achieved in linear time-hence, this is no more intractable than the situation in ordinary databases. Finally, we identify necessary and sufficient conditions for the database to be able to preserve security. Similar results are also obtained for yes-no-don't know dialogs  相似文献   

7.
Data dictionaries are playing an increasingly important role as repositories for information about all the data belonging to an organisation. Through the provision of sophisticated end user facilities, database management system implementors are encouraging high-level interface access to databases. However, it is often alleged that this type of database access is very costly. In this paper we describe the use of a data dictionary in the implementation of a high-level query interface to CODASYL databases. A feature of the query interface is its use of database monitoring information, stored in the data dictionary, to optimise the processing of queries.  相似文献   

8.
In this article, we present a comprehensive approach for privacy preserving access control based on the notion of purpose. In our model, purpose information associated with a given data element specifies the intended use of the data element. A key feature of our model is that it allows multiple purposes to be associated with each data element and also supports explicit prohibitions, thus allowing privacy officers to specify that some data should not be used for certain purposes. An important issue addressed in this article is the granularity of data labeling, i.e., the units of data with which purposes can be associated. We address this issue in the context of relational databases and propose four different labeling schemes, each providing a different granularity. We also propose an approach to represent purpose information, which results in low storage overhead, and we exploit query modification techniques to support access control based on purpose information. Another contribution of our work is that we address the problem of how to determine the purpose for which certain data are accessed by a given user. Our proposed solution relies on role-based access control (RBAC) models as well as the notion of conditional role which is based on the notions of role attribute and system attribute.  相似文献   

9.
10.
This approach proposes the creation and management of adaptive learning systems by combining component technology, semantic metadata, and adaptation rules. A component model allows interaction among components that share consistent assumptions about what each provides and each requires of the other. It allows indexing, using, reusing, and coupling of components in different contexts powering adaptation. Our claim is that semantic metadata are required to allow a real reusing and assembling of educational component. Finally, a rule language is used to define strategies to rewrite user query and user model. The former allows searching components developing concepts not appearing in the user query but related with user goals, whereas the last allow inferring user knowledge that is not explicit in user model.John Freddy Duitama received his M.Sc. degree in system engineering from the University of Antioquia -Colombia (South America). He is currently a doctoral candidate in the GET – Institut National des Télécommunications, Evry France. This work is sponsored by the University of Antioquia, where he is assistant professor.His research interest includes semantic web and web-based learning systems, educational metadata and learning objects.Bruno Defude received his Ph.D. in Computer Science from the University of Grenoble (I.N.P.G) in 1986. He is currently Professor in the Department of Computer Science at the GET - Institut National des Télécommunications, Evry France where he leads the SIMBAD project (Semantic Interoperability for MoBile and ADaptive applications).His major field of research interest is databases and semantic web, specifically personalized data access, adaptive systems, metadata, interoperability and semantic Peer-to-peer systems with elearning as a privileged application area.He is a member of ACM SIGMOD.Amel Bouzeghoub received a degree of Ph.D. in Computer Sciences at Pierre et Marie Curie University, France.In 2000, she joined the Computer Sciences Department of GET-INT (Institut National des Telecommunications) at Evry (France) as an associate professor.Her research interests include topics related to Web-based Learning Systems, Semantic Metadata for learning resources, Adaptive Learning Systems and Intelligent Tutoring Systems.Claire Lecocq received an Engineer Degree and a Ph.D. in Computer Sciences respectively in 1994 and 1999. In 1997, she joined the Computer Sciences Department at GET-INT (Institut National des Télécommunications) of Evry, France, as an associate professor. Her first research interests included spatial databases and visual query languages. She is now working on adaptive learning systems, particularly on semantic metadata and user models.  相似文献   

11.
This paper presents a visual query language called VQL for interacting with an object-oriented schema-intensive data model. VQL allows convenient access to the various types of knowledge captured by the semantic model. It consists of a set of “graphical primitives” along with a combination grammar for creating graphical queries. The visual language is internally supported by a prolog-like predicate based query language. The formal grammar underlying the predicate based language is also presented. Apart from being able to create simple queries that can be specified in SQL or QBE, VQL can be used for making queries on any object-oriented data model including the generalization of the E-R model. VQL also handles complicated, indirect queries, specially those that require a reasoning system for query interpretation and response generation. Further, recursive queries on graph structures such as finding transitive closures of graphs may be easily specified. Perhaps the most powerful feature of VQL is its ability to provide high semantic expressibility (in being able to specify highly complex queries) while maintaining simplicity in the user's query formulation process. VQL is embedded in an object-oriented graphical database interaction environment that supports schema creation and manipulation in addition to database querying and updation. The prototype has been implemented in Smalltalk-80 running on a Sun 3/60 workstation. All the illustrations of visual interaction presented are taken from actual interaction sessions  相似文献   

12.
《Information Systems》2000,25(5):367-391
An important issue for the success of a database application is the effectiveness of its interface. Frequently a relevant part of the programming effort is devoted to the generation of interfaces. The visual programming environments reduce only partly this effort, and in particular, things become more complicated when data coming from different sources (different views in the same database or even views from different databases or systems) are to be related and must cooperate in the data navigation and manipulation task. To overcome this problem we present a new database access paradigm based on an algebra on the domain of computational abstractions called “services” which include both dimensions: the data access computation and the user interaction. This means that the interaction is not implemented by using separated constructs as happens for traditional computational models; on the contrary, as the interaction is an integral part of the service paradigm, the user interaction is computed starting from the declarative specification of the data access itself. The combination of services in a service expression through the operators defined by the service algebra makes it possible to generate cooperating user interfaces for complex data navigation and manipulation. Through algebraic properties, which hold both from the data and user interface point of view, the service expressions can be simplified and optimized guaranteeing their initial semantics. The paper shows the application of the service algebra to the relational environment by means of a simple extension to SQL. Finally, the paper describes a tool based on a three tier architecture and on Java technology for developing and distributing services in Web environment. Services and combination of services expressed with the service algebra are automatically translated into Java objects, allowing the rapid development of platform independent data access services.  相似文献   

13.
When a database increases in size, retrieving the data becomes a major problem. An approach based on data visualization and visual reasoning is described. The main idea is to transform the data objects and present sample data objects in a visual space. The user can use a visual language to incrementally formulate the information retrieval request in the visual space. A prototype system is described with the following features: (1) it is built on top of the SIL-ICON visual language compiler and therefore can be customized for different application domains; (2) it supports a fuzzy icon grammar to define reasonable visual sentences; (3) it incorporates a semantic model of the database for fuzzy visual query translation; and (4) it incorporates a VisualNet which stores the knowledge learned by the system in its interaction with the user so that the VisualReasoner can adapt its behavior  相似文献   

14.
The need to provide effective tools for analyzing and querying spatial data is becoming increasingly important with the explosion of data in applications such as geographic information systems, image databases, CAD, and remote sensing. The SEE (Spatial Exploration Environment) is the first effort at applying direct-manipulation visual information seeking (VIS) techniques to spatial data analysis by visually querying as well as browsing spatial data and reviewing the visual results for trend analysis. The SEE system incorporates a visual query language (SVIQUEL) that allows users to specify the relative spatial position (both topology and direction) between objects using direct manipulation. The quantitative SVIQVEL sliders (S-sliders) are complemented by the qualitative active-picture-for-querying (APIQ) interface that allows the user to specify qualitative relative position queries. APIQ provides qualitative visual representations of the quantitative query specified by the S-sliders. This increases the utility of the system for spatial browsing and spatial trend discovery with no particular query in mind. The SVIQUEL queries are processed using a k-Bucket index structure specifically tuned for incremental processing of the multidimensional range queries that represent the class of queries that can be expressed by SVIQUEL. We have also designed a tightly integrated map visualization that helps to preserve the spatial context and a bar visualization that provides a qualitative abstraction of aggregates  相似文献   

15.
In this article we present ConQueSt, a constraint-based querying system able to support the intrinsically exploratory (i.e., human-guided, interactive and iterative) nature of pattern discovery. Following the inductive database vision, our framework provides users with an expressive constraint-based query language, which allows the discovery process to be effectively driven toward potentially interesting patterns. Such constraints are also exploited to reduce the cost of pattern mining computation. ConQueSt is a comprehensive mining system that can access real-world relational databases from which to extract data. Through the interaction with a friendly graphical user interface (GUI), the user can define complex mining queries by means of few clicks. After a pre-processing step, mining queries are answered by an efficient and robust pattern mining engine which entails the state-of-the-art of data and search space reduction techniques. Resulting patterns are then presented to the user in a pattern browsing window, and possibly stored back in the underlying database as relations.  相似文献   

16.
17.
Internet上的化学数据库是重要的专业资源,基于超链接分析的搜索引擎还不能索引这类资源。本论文以充分利用Internet上的化学数据库数据为目标,将“一个查询发动多个同级检索引擎,并以结构化的方式组织信息”的方案应用于以化合物标识信息为检索入口的Web化学数据库,建立了一个基于多站点集成检索的Web数据库定向查询引擎。该引擎是一个包括用户交互层、中间检索层、数据提供层的三层Web模型。各层在系统内部分别对应于响应用户检索请求的客户端代理模块、集成远程Web信息的服务器端代理模块,以及提供缓存和检索的关系数据库模块。模型采用JSP+Java组件的开发方式,在HTTP协议标准发送方法的基础上,采用XML技术对检索返回文档进行结构化数据的提取和表示,利用XML—DBMS实现XML数据的存储和检索,建立了一套针对深层Web数据交换的解决方案。依此方案所建立的ChemDB Portal Search实现了四个分布式Web化学数据库的有效加入、同时检索和统一显示。该系统是针对深层Web信息的挖掘和集成检索的一次尝试,它可为其它领域建立类似的系统提供借鉴。  相似文献   

18.
We discuss an adaptive approach towards Content-Based Image Retrieval. It is based on the Ostensive Model of developing information needs—a special kind of relevance feedback model that learns from implicit user feedback and adds a temporal notion to relevance. The ostensive approach supports content-assisted browsing through visualising the interaction by adding user-selected images to a browsing path, which ends with a set of system recommendations. The suggestions are based on an adaptive query learning scheme, in which the query is learnt from previously selected images. Our approach is an adaptation of the original Ostensive Model based on textual features only, to include content-based features to characterise images. In the proposed scheme textual and colour features are combined using the Dempster-Shafer theory of evidence combination. Results from a user-centred, work-task oriented evaluation show that the ostensive interface is preferred over a traditional interface with manual query facilities. This is due to its ability to adapt to the user's need, its intuitiveness and the fluid way in which it operates. Studying and comparing the nature of the underlying information need, it emerges that our approach elicits changes in the user's need based on the interaction, and is successful in adapting the retrieval to match the changes. In addition, a preliminary study of the retrieval performance of the ostensive relevance feedback scheme shows that it can outperform a standard relevance feedback strategy in terms of image recall in category search.  相似文献   

19.
We define the query language Vizla, in which answers to queries are built up by pointing to representations of sets and functions in a conceptual model of the data base of an application, and to iconic identifiers of computational operators or control constructs. At its present stage of development the primary use of Vizla is in the validation of conceptual models of information systems, but it is to be developed into a user interface to SF, a prototyping language for information and control systems. Moreover, it can be regarded as a visual programming language in its own right. As such it is based on abstract data types  相似文献   

20.
Biological databases contain a large amount of data about metabolic pathways, in particular about similar pathways in different species. Biologists are familiar with visual representations of metabolic pathways. Pathway diagrams help them to understand the complex relationships between the components of the pathways, to extract information from the data, and to compare pathways between different species. However, visual interfaces to metabolic pathway databases cannot cope well with the visual comparison of similar pathways in different species.This paper presents a new approach for the visual comparison of metabolic pathways which uses a graph drawing algorithm. Using layout constraints, identical parts of similar pathways in different species are placed side by side, thereby highlighting similarities and differences between these pathways. This visualization method can be used as a visual interface to databases. It supports different layout styles and has been tested with data obtained from the BioPath system and the KEGG database.  相似文献   

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