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We propose a “logic + SQL” framework for set preferences. Candidate best sets are represented using profiles consisting of scalar features. This reduces set preferences to tuple preferences over set profiles. We propose two optimization techniques: superpreference and M-relation. Superpreference targets dominated profiles. It reduces the input size by filtering out tuples not belonging to any best...
This paper deals with the negation operator in the context of a bipolar fuzzy relational algebra which makes it possible to handle bipolar fuzzy queries (involving flexible constraints and wishes) and relations. Several possible definitions of the negation are studied and assessed with respect to some desirable properties. A negation operator which complies with all those desirable properties is proposed,...
We propose a possibility theory-based approach to the treatment of missing user preferences in skyline queries. To compensate this lack of knowledge, we show how a set of plausible preferences suitable for the current context can be derived either in a case-based reasoning manner, or using an extended possibilistic logic setting. Uncertain dominance relationships are defined in a possibilistic way...
LDAP Multi-Master Technique is a replication approach using Syncrepl to replicate data to multiple servers. As the specialized database optimized for read access, the directory is used to represent heterogeneous entities in directory information tree (DIT). Compared with existing Sync replication models, the directory template replication model based on query templates proposed in this paper only...
Result caching is an efficient technique for reducing the query processing load, hence it is commonly used in search engines. In this paper, we study query result caching and proposes a cache management policy for achieving higher hit ratios compared to traditional heuristics methods. Our cache management policy comprises an eviction policy and an admission policy, and it divides the memory allocated...
Leveraging query logs benefits the users analyzing large data warehouses. But so far nothing exists to allow the user to have concise and usable representation of what is in the log. In this paper, we propose a framework for summarizing OLAP query logs. This framework is based on the idea that a query can summarize another query and that a log can summarize another log. It includes a simple language...
An ability to account for positive and negative information in the representation of user preferences and intentions is an important facility that can enhance the functionality and usefulness of flexible database querying systems. This is in line with a growing interest in preference modeling. Bipolarity, as a formal representation of positive and negative information, is one of crucial factors in...
To deal with the problem of too many answers returned from a Web database in response to a user query, this paper proposes a novel categorization approach which takes advantages of the user contextual preferences to construct a navigational tree in order to reduce the information overload. Based on the user original query, we first speculate how much the user cares about each attribute in the specified...
In this paper, we describe an approach to database preference queries based on the notion of fuzzy outranking, suited to the case where partial preferences are incommensurable. This model constitutes an alternative to the use of Pareto order. Even though outranking does not define an order in the strict sense of the term, we describe a technique which yields a complete pre-order, based on a global...
Evaluating a boolean conjunctive query q over a guarded first-order theory T is equivalent to checking whether (T & not q) is unsatisfiable. This problem is relevant to the areas of database theory and description logic. Since q may not be guarded, well known results about the decidability, complexity, and finite-model property of the guarded fragment do not obviously carry over to conjunctive...
In this paper, we consider the situation where a fuzzy query is submitted to distributed data sources. In order to save bandwith and processing cost, we propose a technique whose aim is to forward the query to the most relevant sources only. It is assumed that a fuzzy summary of every data source is available, and the approach we propose consists in estimating the relevance of a source wrt to a user...
Advances in wireless communication and powerful computing technologies will eventually lead to a digital environment in which computing functionality will be embedded in all kinds of objects, which are capable of recognizing and responding to individual needs in a seamless, unobtrusive, and often invisible way. Such a vision was coined Ambient Intelligence (AmI), whose aim is to bring information...
The development of Internet calls urgently for the ability to deal with massive textually represented geographical knowledge. Digital Gazetteer Service (DGS) plays a foundational role in this process. To help users to check and confirm the proper places quickly and efficiently, one of the key points of DGS is to rank place names according to their satisfaction with query conditions set by users. Match...
Query term suggestion that interactively expands the queries is an indispensable technique to help users formulate high-quality queries and has attracted much attention in the community of web search. Existing methods usually suggest terms based on statistics in documents as well as query logs and external dictionaries, and they neglect the fact that the topic information is very crucial because it...
The term Deep Web (sometimes also called Hidden Web) refers to the data content that is created dynamically as the result of a specific search on the Web. In this respect, such content resides outside web pages, and is only accessible through interaction with the web site typically via HTML forms. It is believed that the size of the Deep Web is several orders of magnitude larger than that of the so-called...
This paper provides a comprehensive analysis of algorithms for spatio-temporal pattern mining, which helps to select appropriate algorithms for a given Moving Objects Database. We can distinguish basic and extended comparing functions. The basic ones correspond to research fields related to pattern mining. The extended comparing functions extend the analysis to additional aspects. All these functions...
Context-aware database is frequently used in user-centric applications. The users normally tend to express their preferences through comparisons. For example, Bob prefers Cornell to USC. Because the users only compare a small proportion of the products under difference contexts, ??incomplete?? preferences are a common occurrence. We propose a ranking approach which can contextually rank the query...
For the majority college students in Taiwan, learning and using terminologies of a specific domain between Chinese and English interchangeably are quite a challenge. Most of the students seek for assistances from library resources or search for answers on web. Unfortunately, the students would not be able to identify the correctness of their findings, or the worse, the students cannot choose the right...
The ability to provide both rich and natural answers with respect to a given question, and clear explanations for failures, is a crucial aspect for a future generation of question answering systems able to interact with a user. We argue that such abilities are necessarily based on a deep analysis of the content of both the question and the answer, and propose an ontology-based approach to represent...
Conventional database selection algorithms are very helpful in improving search results and reducing network overhead and computation time by cutting off databases that are irrelevant to the queries. However, they have not been designed to adapt to the changing interest and intentions of users in the document retrieval process. In this paper, we propose an adaptive search system using heterogeneous...
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