Schema integration as part of the database design as well as of the database integration process has to deal with extensional relationships among classes of the di erent schemata to be integrated. As a rule, the extensional relationships must be speci ed by the database designer. Partially, some relationships may also be derived from other relationships. Most existing schema integration approac...

Several recent techniques and tools for Ontology-based Data Access (OBDA) make use of the so-called extensional constraints (a.k.a. ABox dependencies). So far, extensional constraints have been mainly considered in a setting where data are represented in an ABox, instead of external data sources connected to the ontology through declarative mappings. Moreover, the issue of how to generate exten...

This will be a discussion of the non-invasive determination of the viscosity of a non-Newtonian fluid in laminar pipe flow over the range of shear rates present in the pipe. The procedure used requires knowledge of the flow profile in and the pressure drop along a long straight run of pipe. The profile is determined by using a pulsed ultrasonic Doppler velocimeter. This approach is ideal for ma...

■ Abstract Filament-stretching rheometers are devices for measuring the extensional viscosity of moderately viscous non-Newtonian fluids such as polymer solutions. In these devices, a cylindrical liquid bridge is initially formed between two circular end-plates. The plates are then moved apart in a prescribed manner such that the fluid sample is subjected to a strong extensional deformation. As...

reluctance towards implementation of precision agriculture (pa) seems to be based on lackof consideration to education, extension, and research sectors. the objective of this study isto identify educational, extensional, and research requirements in application of the pasystem. the research population included all the experts in qazvin province who are familiarwith pa concepts and pa’s equipmen...

This historical review takes a few selected issues from the rheological studies of extensional flow that fill the literature, starting with extracts from the seminal papers of Trouton (Proc. Roy. Soc. A77 (1906) 426-440) and Fano (Archivio di fisiologio, 5 (1908) 365-370). Work in the first half of the twentieth century on spinnability and extensional viscosity measurement is highlighted, follo...

This paper studies confluence properties of extensional and non-extensional λ-calculi with explicit substitutions, where extensionality is interpreted by η-expansion. For that, we propose a general scheme for explicit substitutions which describes those abstract properties that are sufficient to guarantee confluence. Our general scheme makes it possible to treat at the same time many well-known...

Logical policy-based access control models are greatly expressive and thus provide the flexibility for administrators to represent a wide variety of authorization policies. Extensional access control models, on the other hand, utilize simple data structures to better enable a less trained and non-administrative workforce to participate in the day-to-day operations of the system. In this paper, ...