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Index Structures for Path Expressions

by Tova Milo, Dan Suciu , 1997
"... In recent years there has been an increased interest in managing data which does not conform to traditional data models, like the relational or object oriented model. The reasons for this non-conformance are diverse. One one hand, data may not conform to such models at the physical level: it may be ..."
Abstract - Cited by 333 (7 self) - Add to MetaCart
] and path indexes 4]. In the case of semistructured data, queries are even more complex, because they may contain generalized path expressions 1, 7, 8, 16]. The additional exibility is needed in order to traverse data whose structure is irregular, or partially unknown to the user.

Indexing and Querying XML Data for Regular Path Expressions

by Quanzhong Li, Bongki Moon - IN VLDB , 2001
"... With the advent of XML as a standard for data representation and exchange on the Internet, storing and querying XML data becomes more and more important. Several XML query languages have been proposed, and the common feature of the languages is the use of regular path expressions to query XML ..."
Abstract - Cited by 343 (9 self) - Add to MetaCart
With the advent of XML as a standard for data representation and exchange on the Internet, storing and querying XML data becomes more and more important. Several XML query languages have been proposed, and the common feature of the languages is the use of regular path expressions to query XML

The specification of process synchronization by path expressions

by R. H. Campbell, A. N. Habermann - in Operating Systems, E. Gelenbe and , 1974
"... A new method of expressing synchronization is presented and the motivations and considerations which led to this method are explained. Synchronization rules, given by 'path expressions', are incorporated into the type definitions which are used to introduce data objects shared by several a ..."
Abstract - Cited by 144 (1 self) - Add to MetaCart
A new method of expressing synchronization is presented and the motivations and considerations which led to this method are explained. Synchronization rules, given by 'path expressions', are incorporated into the type definitions which are used to introduce data objects shared by several

Access path selection in a relational database management system

by P. Griffiths Selinger, M. M. Astrahan, D. D. Chamberlin, It. A. Lorie, T. G. Price , 1979
"... ABSTRACT: In a high level query and data manipulation language such as SQL, requests are stated non-procedurally, without reference to access paths. This paper describes how System R chooses access paths for both simple (single relation) and complex queries (such as joins), given a user specificatio ..."
Abstract - Cited by 587 (1 self) - Add to MetaCart
ABSTRACT: In a high level query and data manipulation language such as SQL, requests are stated non-procedurally, without reference to access paths. This paper describes how System R chooses access paths for both simple (single relation) and complex queries (such as joins), given a user

Optimizing Branching Path Expressions

by Jason Mchugh, Jennifer Widom , 1999
"... Path expressions form the basis of most query languages for semistructured data and XML, specifying traversals through graph-based data. We consider the query optimization problem for path expressions that "branch," or specify traversals through two or more related subgraphs; such expres ..."
Abstract - Cited by 10 (0 self) - Add to MetaCart
Path expressions form the basis of most query languages for semistructured data and XML, specifying traversals through graph-based data. We consider the query optimization problem for path expressions that "branch," or specify traversals through two or more related subgraphs

Evaluating Queries with Generalized Path Expressions

by Vassilis Christophides, Sophie Cluet, Guido Moerkotte - In Proceedings of the ACM SIGMOD International Conference on Management of Data , 1996
"... In the past few years, query languages featuring generalized path expressions have been proposed. These languages allow the interrogation of both data and structure. They are powerful and essential for a number of applications. However, until now, their evaluation has relied on a rather naive and in ..."
Abstract - Cited by 73 (16 self) - Add to MetaCart
In the past few years, query languages featuring generalized path expressions have been proposed. These languages allow the interrogation of both data and structure. They are powerful and essential for a number of applications. However, until now, their evaluation has relied on a rather naive

Access to objects by path expressions and rules

by Jürgen Frohn, Georg Lausen, Heinz Uphoff - PROC. INTL. CONFERENCE ON VERY LARGE DATA BASES, SANTIAGO DE CHILE , 1994
"... Object oriented databases provide rich structuring capabilities to organise the objects being relevant for a given application. Due to the possible complexity of object structures, path expressions have become accepted as a concise syntactical means to reference objects. Even though known approaches ..."
Abstract - Cited by 44 (12 self) - Add to MetaCart
Object oriented databases provide rich structuring capabilities to organise the objects being relevant for a given application. Due to the possible complexity of object structures, path expressions have become accepted as a concise syntactical means to reference objects. Even though known

Querying object-oriented databases

by Michael Kifer, Won Kim, Yehoshua Sagiv - ACM SIGMOD INTERNATIONAL CONFERENCE ON MANAGEMENT OF DATA , 1992
"... We present a novel language for querying object-oriented databases. The language is built around the idea of extended path expressions that substantially generalize [ZAN83], and on an adaptation of the first-order formalization of object-oriented languages from [KW89, KLW90, KW92]. The language inco ..."
Abstract - Cited by 492 (6 self) - Add to MetaCart
We present a novel language for querying object-oriented databases. The language is built around the idea of extended path expressions that substantially generalize [ZAN83], and on an adaptation of the first-order formalization of object-oriented languages from [KW89, KLW90, KW92]. The language

Randomized kinodynamic planning

by Steven M. Lavalle, James J. Kuffner, Jr. - THE INTERNATIONAL JOURNAL OF ROBOTICS RESEARCH 2001; 20; 378 , 2001
"... This paper presents the first randomized approach to kinodynamic planning (also known as trajectory planning or trajectory design). The task is to determine control inputs to drive a robot from an initial configuration and velocity to a goal configuration and velocity while obeying physically based ..."
Abstract - Cited by 626 (35 self) - Add to MetaCart
dynamical models and avoiding obstacles in the robot’s environment. The authors consider generic systems that express the nonlinear dynamics of a robot in terms of the robot’s high-dimensional configuration space. Kinodynamic planning is treated as a motion-planning problem in a higher dimensional state

On limits of wireless communications in a fading environment when using multiple antennas

by G. J. Foschini, M. J. Gans - Wireless Personal Communications , 1998
"... Abstract. This paper is motivated by the need for fundamental understanding of ultimate limits of bandwidth efficient delivery of higher bit-rates in digital wireless communications and to also begin to look into how these limits might be approached. We examine exploitation of multi-element array (M ..."
Abstract - Cited by 2426 (14 self) - Add to MetaCart
communication links. We explore the important case when the channel characteristic is not available at the transmitter but the receiver knows (tracks) the characteristic which is subject to Rayleigh fading. Fixing the overall transmitted power, we express the capacity offered by MEA technology and we see how
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