Another Word For It Patrick Durusau on Topic Maps and Semantic Diversity

July 1, 2012

The observational roots of reference of the semantic web

Filed under: Identity,Semantic Web,Semantics — Patrick Durusau @ 4:42 pm

The observational roots of reference of the semantic web by Simon Scheider, Krzysztof Janowicz, and Benjamin Adams.

Abstract:

Shared reference is an essential aspect of meaning. It is also indispensable for the semantic web, since it enables to weave the global graph, i.e., it allows different users to contribute to an identical referent. For example, an essential kind of referent is a geographic place, to which users may contribute observations. We argue for a human-centric, operational approach towards reference, based on respective human competences. These competences encompass perceptual, cognitive as well as technical ones, and together they allow humans to inter-subjectively refer to a phenomenon in their environment. The technology stack of the semantic web should be extended by such operations. This would allow establishing new kinds of observation-based reference systems that help constrain and integrate the semantic web bottom-up.

In arguing for recasting the problem of semantics as one of reference, the authors say:

Reference systems. Solutions to the problem of reference should transgress syntax as well as technology. They cannot solely rely on computers but must also rely on human referential competences. This requirement is met by reference systems [22]. Reference systems are different from ontologies in that they constrain meaning bottom-up [11]. Most importantly, they are not “yet another chimera” invented by ontology engineers, but already exist in various successful variants.

I rather like the “human referential competences….”

After all, useful semantic systems are about references that we recognize.

SkyQuery: …Parallel Probabilistic Join Engine… [When Static Mapping Isn’t Enough]

Filed under: Astroinformatics,Bayesian Data Analysis,Dynamic Mapping,Identity,Merging,SQL — Patrick Durusau @ 4:41 pm

SkyQuery: An Implementation of a Parallel Probabilistic Join Engine for Cross-Identification of Multiple Astronomical Databases by László Dobos, Tamás Budavári, Nolan Li, Alexander S. Szalay, and István Csabai.

Abstract:

Multi-wavelength astronomical studies require cross-identification of detections of the same celestial objects in multiple catalogs based on spherical coordinates and other properties. Because of the large data volumes and spherical geometry, the symmetric N-way association of astronomical detections is a computationally intensive problem, even when sophisticated indexing schemes are used to exclude obviously false candidates. Legacy astronomical catalogs already contain detections of more than a hundred million objects while the ongoing and future surveys will produce catalogs of billions of objects with multiple detections of each at different times. The varying statistical error of position measurements, moving and extended objects, and other physical properties make it necessary to perform the cross-identification using a mathematically correct, proper Bayesian probabilistic algorithm, capable of including various priors. One time, pair-wise cross-identification of these large catalogs is not sufficient for many astronomical scenarios. Consequently, a novel system is necessary that can cross-identify multiple catalogs on-demand, efficiently and reliably. In this paper, we present our solution based on a cluster of commodity servers and ordinary relational databases. The cross-identification problems are formulated in a language based on SQL, but extended with special clauses. These special queries are partitioned spatially by coordinate ranges and compiled into a complex workflow of ordinary SQL queries. Workflows are then executed in a parallel framework using a cluster of servers hosting identical mirrors of the same data sets.

Astronomy is a cool area to study and has data out the wazoo, but I was struck by:

One time, pair-wise cross-identification of these large catalogs is not sufficient for many astronomical scenarios.

Is identity with sharp edges, susceptible to pair-wise mapping, the common case?

Or do we just see some identity issues that way?

Commend the paper to you as an example of dynamic merging practice.

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