共查询到20条相似文献,搜索用时 15 毫秒
1.
Data curation activities in collaborative databases mandate that collaborators interact until they converge and agree on the content of their data. In a previous work, we presented a cloud-based collaborative database system that promotes and enables collaboration and data curation scenarios. Our system classifies different versions of a data item to either pending, approved, or rejected. The approval or rejection of a certain version is done by the database Principle Investigators (or PIs) based on its value. Our system also allows collaborators to view the status of each version and help PIs take decisions by providing feedback based on their experiments and/or opinions. Most importantly, our system provided mechanisms for history tracking of different versions to trace the modifications and approval/rejection done by both collaborators and PIs on different versions of a data item. We labeled our system as Update-Pending-Approval model (or UPA). In this paper, we describe a high level SQL query interface language for PIs and collaborators to interact with the UPA framework. We define a set of UPA keywords that are used as a part of the history tracking mechanism to select specific versions of a data item, and a set of UPA options that select specific versions based on possible future decisions of PIs. We implemented our query interface mechanism on top of Apache Phoenix, taking into consideration that the UPA system was implemented on top of Apache HBase. We test the performance of the UPA query language by executing several queries that contain different complexity levels and discuss their results. 相似文献
2.
越来越多的信息隐藏在Web查询接口之后,在此情况下如何寻找与用户查询最相关的数据源接口就变得越来越重要。文中提出了一种Deep Web查询接口选择算法,该算法是完全依赖于查询接口特征的。给定大量异构的Deep Web数据源,目标是选择与用户查询最相关的查询接口集。通过对实际查询接口特征的观察,发现了查询接口上谓词间的相关性。基于此发现,设计了一种基于共同出现谓词相关度模型的数据源选择算法,用于选择与用户查询最相关的查询接口集。 相似文献
3.
FLEX a user interface to relational databases, can be used satisfactorily by users with different levels of expertise. FLEX is based on a formal query language, but is tolerant of incorrect input. It never rejects queries; instead, it adapts flexibility and transparently to their level of correctness and well-formedness, providing interpretations of corresponding accuracy and specificity. The most prominent design feature of FLEX is the smooth concatenation of several independent mechanisms, each capable of handling input of decreasing level of correctness and well-formedness. Each input is cascaded through this series of mechanisms until an interpretation is found. FLEX is also cooperative. It never delivers empty answers without explanation or assistance. By following up each failed query with a set of more general queries, FLEX determines whether an empty answer is genuine, in which case it suggests related queries that have nonempty answers, or whether it reflects erroneous presuppositions on the part of the user, in which case it then explains them 相似文献
4.
Location-aware computing technology becomes promising for pervasive personalization services which run anytime, anywhere, and on any device. These services should be based on contextual queries that are provided in a fast and flexible manner. To do so, cooperative query answering may be useful to support query relaxation and to provide both approximate matches as well as exact matches. To facilitate query relaxation, a knowledge representation framework has been widely adopted which accommodates semantic relationships or distance metrics to represent similarities among data values. However, research shows few legacy cooperative query mechanisms that consider location-awareness. Hence, the purpose of this paper is to propose a securely personalized location-aware cooperative query that supports conceptual distance metric among data values, while considering privacy concerns around user context awareness. To show the feasibility of the methodology proposed in this paper, we have implemented a prototype system, LACO, in the area of site search in an actual large-scale shopping mall. 相似文献
5.
It has been now well over thirty years since the advent of visual query systems (VQSs). Following a very active research period spanning from the late 1980s to the early 1990s, key research areas still remain, such as how to express complex queries in user-friendly fashion using a form-based query interface. A query is considered potentially complex from the user׳s point of view when it contains several entity sets and involves an aggregate operator and/or a many-to-many relationship set. This work examines such complex queries in the light of a form-based VQS, called OVI-2, and developed to handle the sophisticated query needs of users of the student records system at Aalto University, Otaniemi campus.Special emphasis is given to complex queries which involve existential quantification or its negation, such as finding students who have completed one given set of courses but who have not yet completed another given set of courses. User-friendliness was a key priority and was achieved mainly by using a two-phased approach for querying. The first stage focuses on retrieving all tuples and attributes that may be of interest, while in the second stage, users narrow down the set of tuples and select only the attributes that are actually needed.Although the presented VQS has been specifically developed for use with a student database, the key ideas are described in a generic way which should allow them to be used to query almost any database schema that has a many-to-many relationship set. Because OVI-2 was in active use for more than five years (over forty users had access to it), user feedback played a big role in this work. Many of the conclusions presented herein are based on observing users actually using OVI-2 to perform their timely query needs. 相似文献
6.
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
8.
查询功能是管理信息系统的重要组成部分,是评判管理信息系统性能的重要因素。系统中数据的复杂多样,决定了针对这些数据的查询也应该是多样的。文章根据查询内容分析了查询的种类,并给出了在某管理信息系统中的实现方法。 相似文献
10.
In this paper, we present a three-dimensional user interface for synchronous co-operative work, Spin, which has been designed for multi-user synchronous real-time applications to be used in, for example, meetings and learning situations. Spin is based on a new metaphor of virtual workspace. We have designed an interface, for an office environment, which recreates the three-dimensional elements needed during a meeting and increases the user's scope of interaction. In order to accomplish these objectives, animation and three-dimensional interaction in real time are used to enhance the feeling of collaboration within the three-dimensional workspace. Spin is designed to maintain a maximum amount of information visible. The workspace is created using artificial geometry — as opposed to true three-dimensional geometry — and spatial distortion, a technique that allows all documents and information to be displayed simultaneously while centring the user's focus of attention. Users interact with each other via their respective clones, which are three-dimensional representations displayed in each user's interface, and are animated with user action on shared documents. An appropriate object manipulation system (direct manipulation, 3D devices and specific interaction metaphors) is used to point out and manipulate 3D documents. 相似文献
11.
语音识别技术是近年来信息领域重要的科技发展技术之一.作为一门交叉学科,语音识别正逐步成为信息技术中人机接口的关键技术.探讨了为数据库查询提供自然语言接口的可能性,介绍了图书资料查询系统中语音识别的基本框架,并详细描述了采用微软Speech SDK技术实现图书资料查询的详细过程.给出了查询流程,基于状态转换图的词法分析和语法分析方法,将疑问句转换成SQL查询语句的方法,以及由查询结果生成答句的方法. 相似文献
12.
Online information repositories commonly provide keyword search facilities through textual query languages based on Boolean
logic. However, there is evidence to suggest that the syntactic demands of such languages can lead to user errors and adversely
affect the time that it takes users to form queries. Users also face difficulties because of the conflict in semantics between
AND and OR when used in Boolean logic and English language. Analysis of usage logs for the New Zealand Digital Library (NZDL)
show that few Boolean queries contain more than three terms, use of the intersection operator dominates and that query refinement
is common. We suggest that graphical query languages, in particular Venn-like diagrams, can alleviate the problems that users
experience when forming Boolean expressions with textual languages. A study of the utility of Venn diagrams for query specification
indicates that with little or no training users can interpret and form Venn-like diagrams in a consistent manner which accurately
correspond to Boolean expressions. We describe VQuery, a Venn-diagram based user interface to the New Zealand Digital Library
(NZDL). In a study which compared VQuery with a standard textual Boolean interface, users took significantly longer to form
queries and produced more erroneous queries when using VQuery. We discuss the implications of these results and suggest directions
for future work.
Received: 15 December 1997 / Revised: June 1999 相似文献
13.
A new physical query interface is proposed for tangible augmented tagging and interaction using two types of context-aware AR interfaces, visual and invisible interfaces. In visual interfaces, augmented reality markers are utilized for supporting intuitive interactions and manipulations with digital contents. RFID is used as an invisible interface for supporting line-of-sight, direct and query interactions. By combining the advantages of visual and invisible interfaces, more natural interaction with digital contents can be provided, which can remove the difficulty of using typical AR paddles, cubes and gadgets that are widely used in AR interactions. Semantic ontology is adopted in order to effectively support physical querying, filtering and grouping through the combination of multiple RFID tags. The proposed approach has been applied to a variety of multi-media interactions, such as digital product review and digital catalog or book interaction. We show the effectiveness and the advantages of the proposed approach by demonstrating several implementation results and by a usability study. 相似文献
14.
Real-time database management systems have become a hot topic in the research and development community of late (Fort94a,Grah93,WCPP93). In addition there has been a movement in the standards community to examine and develop extensions to existing and proposed query languages to support real-time (Fish94,Fort94,Fort94a,FS94,Gord94).This paper examines the state of research into real-time database management systems in the areas of database structuring, transaction structuring, transaction processing, concurrency control, recovery and real-time transaction scheduling. We then extend the findings and trends of this work into the high level specification of data definition language, data manipulation language and data control language extensions for the standard SQL2 and emerging SQL3 database query languages. 相似文献
15.
Cooperative query answering supports query relaxation and provides approximate answers as well as exact answers. To facilitate the query relaxation, a knowledge representation framework has been widely adopted, which accommodates semantic relationships or distance metrics to represent similarities among data values. In this paper, we propose a metricized knowledge abstraction hierarchy (MKAH) that supports multi-level data abstraction hierarchy and distance metric among data values. We show that the abstraction hierarchy is useful in representing the semantic relationship, and the abstraction hierarchy can provide data values with different scope according to their abstraction levels. The distance metric expresses the semantic similarity among data values with quantitative measure, and thus it enables query results to be ranked. To verify the practicality and effectiveness of the MKAH, we have implemented a prototype system in the area of career job search. Through various experiments, we show that the MKAH provides rich semantic representation and high quality distance measure. Furthermore, the experiments confirm that the domain adopting the MKAH can be compatible with other numeric domains, and that is advantageous in building up large scaled systems. 相似文献
16.
A temporal knowledge graph (TKG) is theoretically a temporal graph. Recently, systems have been developed to support snapshot queries over temporal graphs. However, snapshot queries can only give separate answers. To retrieve forward-backward correlation facts from temporal knowledge graph, cluster query is proposed in this paper. To deal with the query, the logical view and physical model are presented. Subsequently, five corresponding basic query patters of unit matching are studied, and then the complete matchings are also addressed. To improve the query performance, index-based methods and pruning strategies are adopted. Experiments are conducted to evaluate cluster queries on three real datasets. The experimental results show the effectiveness and efficiency of cluster queries on temporal knowledge graphs. 相似文献
17.
通过对现有查询接口的识别方法进行的深入研究,针对计算、维护复杂以及匹配歧义性等问题,提出一种基于标签编码的Deep Web查询接口识别方法。该方法根据查询接口排列的方向性和不规则性进行标签编码并分组,然后以每一个标签组作为一个独立单位进行特征信息识别,提出了简单属性、复合属性的识别方法以及孤立文本的处理方法。通过对标签下标的约束确定与元素匹配的文本,大大减少了文本与元素匹配中需要考虑的文本数量,避免了由大量启发式算法引发的匹配歧义性问题;通过两次聚类有效解决了接口层次嵌套问题。 相似文献
18.
deep web 数据源中的信息可以通过查询提交进行访问,因此分析一个查询接口的查询能力是非常关键的,本文基于原子查询的理念,提出了一种通过识别查询接口上所有原子查询的方法来估计deep web接口查询能力. 相似文献
19.
Different classes of recursive queries in the relational databases are identified. It is shown that existing proposals to extend the relational query languages are either not powerful enough to express queries in many of these classes or use nonfirst normal form constructs. RQL, a recursive database query language that can be used to express recursive queries on all the classes identified, is presented. RQL is based on the relational algebra. In addition to functions that correspond to the standard and extended relational algebra operators, RQL supports functions required to express general recursive queries. The elements of RQL and the ways in which they are used to formulate complicated, but useful, recursive queries are described. The effects of the extensions embodied in RQL on the termination of recursive query evaluation are discussed 相似文献
20.
We introduce G-Log, a declarative query language based on graphs, which combines the expressive power of logic, the modeling power of complex objects with identity and the representation power of graphs. G-Log is a nondeterministic complete query language, and thus allows the expression of a large variety of queries. We compare G-Log to well-known deductive database languages, and find that it is the only nondeterministic and computationally complete language that does not suffer from the copy-elimination problem. G-Log may be used in a totally declarative way, as well as in a “more procedural” way. Thus, it provides an intuitive, flexible graph-based formalism for nonexpert database users 相似文献
|