2,800 research outputs found
Space-Efficient Data-Analysis Queries on Grids
We consider various data-analysis queries on two-dimensional points. We give
new space/time tradeoffs over previous work on geometric queries such as
dominance and rectangle visibility, and on semigroup and group queries such as
sum, average, variance, minimum and maximum. We also introduce new solutions to
queries less frequently considered in the literature such as two-dimensional
quantiles, majorities, successor/predecessor, mode, and various top-
queries, considering static and dynamic scenarios.Comment: 20 pages, 2 figures, submittin
CHORUS Deliverable 2.1: State of the Art on Multimedia Search Engines
Based on the information provided by European projects and national initiatives related to multimedia search as well as domains experts that participated in the CHORUS Think-thanks and workshops, this document reports on the state of the art related to multimedia content search from, a technical, and socio-economic perspective.
The technical perspective includes an up to date view on content based indexing and retrieval technologies, multimedia search in the context of mobile devices and peer-to-peer networks, and an overview of current evaluation and benchmark inititiatives to measure the performance of multimedia search engines.
From a socio-economic perspective we inventorize the impact and legal consequences of these technical advances and point out future directions of research
The NASA Scientific and Technical Information Program: Prologue to the Future
The NASA STI Program offers researchers an infrastructure of people and systems that facilitates access to STI; worldwide. The Program is also NASA's institutional mechanism for disseminating the results of its research and developing activities. Through discussions in 1991, the STI Program formulated its Strategic Plan. The plan gives the Program a renewed sense of direction by focusing on future opportunities, customer requirements and Program goals, along with the changes needed to achieve those goals. The Program provides users access to a massive flow of STI which, in fact, represents the largest collection of aeronautical and space science information in the world. The STI Program products and services are outlined, along with the NASA centers, international operations, and the fact that total quality management drives NASA wide program developments. As is detailed, the NASA STI Program is using its resources as effectively as possible to meet the missing needs of NASA
Content And Multimedia Database Management Systems
A database management system is a general-purpose software system that facilitates the processes of defining, constructing, and manipulating databases for various applications. The main characteristic of the âdatabase approachâ is that it increases the value of data by its emphasis on data independence. DBMSs, and in particular those based on the relational data model, have been very successful at the management of administrative data in the business domain. This thesis has investigated data management in multimedia digital libraries, and its implications on the design of database management systems. The main problem of multimedia data management is providing access to the stored objects. The content structure of administrative data is easily represented in alphanumeric values. Thus, database technology has primarily focused on handling the objectsâ logical structure. In the case of multimedia data, representation of content is far from trivial though, and not supported by current database management systems
The representation and management of evolving features in geospatial databases
Geographic features change over time, this change being the result of some
kind of event or occurrence. It has been a research challenge to represent
this data in a manner that reflects human perception. Most database systems used in geographic information systems (GIS) are relational, and change
is either captured by exhaustively storing all versions of data, or updates
replace previous versions. This stems from the inherent diffculty of modelling geographic objects in relational tables. This diffculty is compounded
when the necessary time dimension is introduced to model how those objects
evolve. There is little doubt that the object-oriented (OO) paradigm holds
signi cant advantages over the relational model when it comes to modelling
real-world entities and spatial data, and it is argued that this contention
is particularly true when it comes to spatio-temporal data. This thesis describes an object-oriented approach to the design of a conceptual model for representing spatio-temporal geographic data, called the Feature Evolution
Model (FEM), based on states and events. The model was used to implement a spatio-temporal database management system in Oracle Spatial, and
an interface prototype is described that was used to evaluate the system by
enabling querying and visualisation
- âŠ