There exists a need for a quick technology intelligence process to visualize, identify and track changes in science and technology for technology driven entities. In order to fill this gap, a methodology to portray a patent citation network of a seminal patent is proposed here. This methodology can be primarily used to determine what sub-technologies contributed to the technology in question, at what period in time and with how much impact. The same can also be extended to identify what sub technologies spun out from the technology/invention and also the application areas of the same. Patent latent variables like strength and similarity are also used to illustrate the development and flow of scientific knowledge in the technology considered. The efficacy of the methodology is demonstrated by considering patents related to light emitting GaN based compound semi-conductor devices technology (Blue LED Technology), and analyzing the findings resulting from the use of the methodology.

1. Relecura Inc.
www.relecura.com
contact@relecura.com September 2014December, 2014
Shanmukha Sreenivas P
Research Engineer
INDUS TechInnovations
Bangalore
Technology analysis using patent citation network of a seminal patent
SECOND INTERNATIONAL CONFERENCE ON BUSINESS ANALYTICS AND INTELLIGENCE (ICBAI-2014), BANGALORE

2. Contents
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• Problem Statement
• Objectives
• Literature Review
• Methodology
• Results
• Conclusions
• Bibliography

3. Problem Statement
• To develop a quick technology intelligence process to visualize, identify and
track changes in science and technology for technology driven entities using
patent data.
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4. Objectives
• To develop a method that can be primarily used to determine –
1. What sub-technologies contributed to the technology in question ?
2. At what period in time ?
3. And with how much impact ?
4. What sub technologies spun out from the technology/invention and also the
application areas of the same.
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5. Key Literature Review
Insights Author
Research on the construction and analysis of a knowledge spillover network using patent
citation data.
Jaffe et al., 1993
The use of patent citations to provide a trace of knowledge transfer. Jaffe et al., 1998
The use of patent citations to detect international technology diffusion. Jaffe et al., 1999
Models of Technology Diffusion Geroski P, 2000
Use of patent citations to analyze competitive advantages to firms. Patel D. et al., 2011
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Methodology

7. Methodology
• A seminal patent related to the technology of interest was identified and the 2
level forward and backward patent citations were extracted.
• Various attributes of the resulting patent set were extracted from the patent
database using Relecura.
• The citation network was rendered using ForceAtlas2 and the Geo Spatial
Layout graph algorithms in order to understand knowledge transfer patterns.
• Patent related variables and proprietary metrics used in the study –
• No. of Forward Citations
• Relecura Patent Quality (a proprietary metric related to patent valuation, quality and monetization potential of each individual patent)
• Relecura Technology Categories
• NBER Tech Categories
• Patent Similarity
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8. Methodology
Data Set
• Patents, their citations, patent variables and proprietary metrics are
extracted from the IP intelligence platform – Relecura.
Software Used
• Relecura
• Gephi
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9. Methodology
• Graph rendering algorithms used
1) Force Atlas2
- Force-directed layout (Jacomy et al., 2014).
- Spring-like attractive forces based on Hooke's law (Fa= -k.d).
- Repulsive forces like those of electrically charged particles based on Coulomb's law (Fr=k/d2).
2) Geo-Spatial Layout
- Nodes pegged in chronological order
- Latitudes
- Longitudes
The above patent citation network methodology was applied to study “Light emitting GaN based compound
semi-conductor devices Technology”.
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Algorithm Variants
Force Atlas2
Forward citations count, NBER categories
Relecura Patent Quality, Relecura Tech Categories
Geo-Spatial Layout
Forward citations count, NBER categories
Relecura Patent Quality, Relecura Tech Categories

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Results

11. Results
Seminal patent chosen –
• For the seminal patent, two level forward and backward citations were
extracted.
• Total patents (Nodes): 2979
• Total connections (Edges): 5302
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Publication
Number
Title Filing
Date
Inventors Original
Assignees
US5578839A Light-emitting gallium
nitride-based compound
semiconductor device
1993-11-17 NAKAMURA
SHUJI et al.
NICHIA CORP

12. Results…1
• Nodes – Patents
• Edges – Citation links
• Knowledge Flow – Clockwise
• Node Size – No. of forward citations
• Node color – NBER tech categorization
• Algorithm – ForceAtlas2
• Observations-
1. A majority of the network nodes belong to the Semiconductor
category with these patents densely co-citing each other.
2. Drugs & Medical Chemistry category (bright turquoise)
patents are also observed as a distinct cluster at the bottom
left indicating that GaN based LEDs have also had a prominent
use in medical applications.
3. The photolithography (dark blue), Lighting (purple) and optics
(magenta) categories are spread across the entire network.
Indicating that these sub-technologies are very closely
associated in developing this technology.
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13. Results…2
• Nodes – Patents
• Edges – Citation links
• Knowledge Flow – Clockwise
• Node Size – Relecura Patent Quality
• Node color – Relecura Technology Category
• Algorithm – ForceAtlas2
• Observations-
1. Many of the highly rated patents pertain to
the categories ‘Electric elements –
Semiconductor devices’ and ‘Electric
Heating and Lighting’.
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14. Results
• On using the ForceAtlas2 algorithm it is not clear as to which fundamental
technologies contributed to the invention and the application areas of the
same.
• Solution – Geo Spatial Layout
• In this Geo-Spatial Layout,
• The Longitudes correspond to the year of filing of the patent.
• The latitudes correspond to different technology buckets.
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15. • Nodes – Patents
• Edges – Citation
links
• Knowledge Flow –
Clockwise
• Node Size – No. of
forward citations
• Node color – NBER
tech categorization
• Algorithm –
GeoSpatial Layout
• Longitudes – Filing
Year
• Latitudes –
Technology buckets
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16. Results…3
• Observations-
1. The tech areas contributing to GaN based LED invention are (From the
backward citations)-
a) Semiconductors
b) Photolithography
c) Optics
d) Domestic Appliances
2. The prominent sub-technologies that spun out of this
invention/technology are (From forwards)-
a) Semiconductors
b) Drugs & Med Chemicals
c) Photolithography
d) Optics
e) Lighting
3. Other sub-technologies that make use of the Blue LED invention, that
show a significant presence in the graph (From forwards) are-
a) Heating & Cooling
b) Chemicals & Polymers
c) Plastics & Wheels
d) Vehicles
e) Cosmetics & Med Chemicals
f) Lab Equipment
g) Metals
h) Measurement
i) Computing
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17. Results…3
• Observations-
4. We can observe that the use of the
Blue LED technology in Drugs and
Med Chemicals started since 1998.
5. This seminal patent led to the filing
of relatively more important patents
in the later years (The bigger nodes to
the right of the seminal patent)
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18. • Nodes – Patents
• Edges – Citation
links
• Knowledge Flow –
Clockwise
• Node Size – No. of
forward citations
• Node color – NBER
tech categorization
• Algorithm –
GeoSpatial Layout
• Longitudes – Filing
Year
• Latitudes –
Technology buckets
• Edge Thickness –
Similar patents
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19. Results…4
• Observations-
• The patents that are relatively
similar are linked with thick edges.
• Not just Semiconductor sub-
technology, a considerable amount
of references are also emanating
from ‘Drugs and Med Chemicals’
sub-technology and thus indicating
its importance.
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20. • Nodes – Patents
• Edges – Citation
links
• Knowledge Flow –
Clockwise
• Node Size –
Relecura Patent
Quality
• Node color –
Relecura Technology
Categories
• Algorithm –
GeoSpatial Layout
• Longitudes – Filing
Year
• Latitudes –
Relecura Technology
Categories
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21. Results…5
• Observations-
• This seminal patent led to the filing
of relatively more important
patents in the later years (The
bigger nodes to the right of the
seminal patent)
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22. • Nodes – Patents
• Edges – Citation links
• Knowledge Flow –
Clockwise
• Node Size – Relecura
Patent Quality
• Node color – Relecura
Technology Categories
• Algorithm –
GeoSpatial Layout
• Longitudes – Filing
Year
• Latitudes – Relecura
Technology Categories
• Edge Thickness –
Similar patents
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23. Results…6
• Observations-
• Dominated with edges emanating
from the patents pertaining to
the category - Electric elements –
Semiconductor devices.
• Significant number of links also
emerged from areas viz. Sealing
materials and drilling fluids;
Nanostructure applications;
Dentistry – Oral care and Crystal
growth.
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Conclusions

25. Conclusions
• This method is a quick technology intelligence process to visualize, identify and
track changes in science and technology for technology driven entities using
patent data.
• This methodology can be primarily used to determine what sub-technologies
contributed to the technology in question, at what period in time and with how
much impact.
• The same can also be extended to identify what sub technologies spun out
from the technology/invention and also in identifying various application areas
of the technology in question.
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Bibliography

27. Bibliography
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Appendix

30. Appendix
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Biologics Domestic appliances Machine Tools Radio, Comm
Catalysis & Separation Drugs, Med Chem Measurement Recording
Chem& Polymers Electric Power Med Instruments Semiconductors
Combustion Engines Food Medical devices Telephone Comm
Computing Furnace Metals Textiles
Construction Heating & Cooling Null Turbines & Engines
Copying & Printing Info Transmission Optics TV, Imaging &Comm
Cosm& Med Chem Lab equipment Photolithography Vehicle parts
Data Commerce Lighting Plastics & Wheels Vehicles
NBER IPC based Technologies
Vehicle lighting & signalling Other Lighting Devices Electric Heating and Lighting
Therapeutic devices - Energy Optical property modification devices Electric Elements - Semiconductor devices
Testing materials Optical elements Electric elements - LASERS
Sterilization, Dressing Non portable lighting devices Displays
Sealing materials and drilling fluids Nano structure applications Dentistry - Oral Care
Printed Circuits Metal Coating Crystal Growth
Plastics Shaping Measurement - Temperature Chemical/Physical processes - catalysis
Pictorial Communication Measurement - Light Carbocyclic compounds
Photography - Camera Light Sources - Others Design patents
Relecura Technology Categories used in study