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Record W2000053898 · doi:10.1109/cloud.2013.78

HGrid: A Data Model for Large Geospatial Data Sets in HBase

2013· article· en· W2000053898 on OpenAlexaff
Dan Han, Eleni Stroulia

Bibliographic record

Venuenot available
Typearticle
Languageen
FieldComputer Science
TopicData Management and Algorithms
Canadian institutionsUniversity of Alberta
Fundersnot available
KeywordsNoSQLComputer scienceScalabilityGeospatial analysisCloud computingData miningGridDatabaseBig dataTree (set theory)

Abstract

fetched live from OpenAlex

Cloud-based infrastructures enable applications to collect and analyze massive amounts of data. Whether these applications are newly developed or they are being evolved from existing RDBMS-based implementations, NoSQL databases offer an attractive platform with which to address this challenge. However, developers find it difficult to effectively manage data in NoSQL databases, because these platforms do not offer much support for data organization. Since poor data organization may abuse the features of the NoSQL database and result in unsatisfactory performance, developing a systematic method for NoSQL database data-schema design is a timely and important problem. In this paper, we focus on geospatial applications, as a family of big-data systems with distinct data types and usage patterns, in need of scalability. We propose the HGrid data model for HBase, based on a hybrid index structure, combining a quad-tree and a regular grid as primary and secondary indices correspondingly. We have comparatively evaluated the performance of HGrid with uniform and skewed data, against two other data models based on quad-tree and regular-grid indices. Our results demonstrate that HGrid scales well and supports efficient performance for range and k-nearest neighbor queries. Although this model does not outperform all its competitors in terms of query response time, it is more flexible for discontinuous and skewed space, and its index requires less space than the corresponding quad-tree and regular-grid indices, which makes its deployment possible with less resources. Through this study, we also formulate a set of guidelines on how to organize data for geospatial applications in HBase.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.003
metaresearch head score (Gemma)0.007
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: none
Teacher disagreement score0.013
Threshold uncertainty score0.025

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0030.007
Meta-epidemiology (narrow)0.0010.001
Meta-epidemiology (broad)0.0010.002
Bibliometrics0.0010.003
Science and technology studies0.0010.001
Scholarly communication0.0040.005
Open science0.0040.002
Research integrity0.0010.002
Insufficient payload (model declined to judge)0.0010.001

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.107
GPT teacher head0.320
Teacher spread0.213 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designSimulation or modeling
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations47
Published2013
Admission routes1
Has abstractyes

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