The patented invention involves a method of compressing labelled trees and supporting efficient research on them.

1. Method of structuring
and compressing
Labeled trees of arbitrary
degree and shape
INVENTORS: Ferragina Paolo
Manzini Giovanni
Muthukrishnan S.
Luccio Fabrizio
PATENT STATUS: GRANTED
PRIORITY NUMBER: US11783288
GRANT DATE: 10/04/2012

2. Invention
The patented invention involves a method of compressing labelled trees and supporting
efficient research on them.
Trees labelling is on the nodes, and the patented technique allows to obtain compression
performance close to the k-order entropy calculated on the content and structure of the
tree.
The operations, that can be performed on the compressed tree, are the navigation of its
structure, or searches for sequences of labels that are needed as paths in the tree. Each
of these operations can be performed efficiently without decompressing the tree
entirely, but acting only on a small portion of it.
The most natural application is compression and search in documents in XML or JSON
format.
The result has been the subject of several scientific publications, published in prestigious
conferences (ACM-SIAM Symp. on Discrete Algorithms and WWW Conference) and
magazines (Journal of the ACM) that have also demonstrated its practical efficiency.

3. Drawings
& pictures Example of the application of patented technique
Example of labelled tree

4. Industrial applications

5. Possible
developments
The research team is available at:
• refine experiments on XML and JSON datasets of interest to the
company;
• find other possible applications of the patented technique that consider
labelled trees coming not only from XML and JSON;
• apply the patented technique to compress and search for other types of
data such as: byte sequences, integers, labeled graphs, or more complex
structures;
• arrive at a software engineering of the prototypes made to obtain the
published experimental results.

6. Tech Transfer Office of University of Pisa
For more information:
Ufficio Regionale di Trasferimento Tecnologico
Headquarters: Via Luigi Carlo Farini, 8 50121 Firenze (FI)
E-mail: urtt@regione.toscana.it
For more information:
Headquarters: Lungarno Pacinotti 43/44, Pisa (PI) 56126
Web site: www.unipi.it/index.php/trasferimento
E-mail: valorizzazionericerca@unipi.it