TwoBinPack - Scala architecture for two-dimensional packing

Operations Research is the science and art of solving practical - often very difficult - problems with mathematical elegance, minimalism and efficiency.

Two-dimensional packing consists of paramount, well-known classes of problems that can arise in a wide variety of contexts - from warehouse stocking to cargo loading, or wood craftsmanship and page layouts, ...

TwoBinPack is a comprehensive Scala architecture, employing hybrid OOP-FP techniques, designed to interactively tackle the above problems and study - via dedicated, extensible analytics tool - how they are usually solved by people, therefore enabling both practical solving and long-term statistical analysis, to gather further insight on the topic.

Last but not least, it is my MSc project in Computer Engineering! ^__^

Official website: http://gianlucacosta.info/TwoBinPack/

Transcript

1. Gianluca Costa
   TwoBinPack
   Scala architecture for two-dimensional packing
   http://gianlucacosta.info/
   

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2. Two-dimensional packing problems
   Knapsack:
   Strip:
   

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3. There are several algorithms, but...
   ...what about
   human reasoning?
   

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4. Main requirements
   We need a dedicated software tool
   Create problem
   instances
   Let users play and
   find solutions
   Gather solutions and
   consult analytics
   We need to…
   

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5. TwoBinPack – ScalaFX apps
   TwoBinManager
   
   Create problem instances
   
   Export problem bundles
   
   Import solutions created by TwoBinGame
   
   Consult analytics
   TwoBinGame
   
   Play with two-dimensional packing problems
   
   Create solution files for TwoBinManager
   

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6. TwoBinPack – Basic workflow
   TwoBinManager TwoBinGame
   Problem Bundle
   User Solutions
   

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7. TwoBinManager – Main window
   

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8. TwoBinGame – Game window
   

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9. Architecture layers
   

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10. Architecture details
    ●
    Written in Scala, with just a handful of POJOs (Plain Old
    Java Objects)
    ●
    ●
    Extensive test coverage; tests are all based on the
    expressive Scalatest framework
    ●
    Open source, published on GitHub under the GPLv3
    license
    OOP FP
    Hybrid
    Architecture
    

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11. Integration with external systems
    TwoBinManager
    External system
    Standard Problem
    

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12. Extensible architecture
    TwoBinManager
    Generators Importers
    Analytics Providers
    

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13. First tests – Setup
    ●
    8 bundles, then 16
    ●
    Each bundle contains 7 problems of different
    estimated difficulty – from fairly easy (but not
    trivial) to very difficult
    ●
    Each problem has a time limit, according to
    the above difficulty
    ●
    User base of ~200 students, at the universities
    of Bologna and Reggio Emilia
    These data are courtesy of the Operations Research groups at Unibo and Unimore.
    

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14. First tests – Result excerpts
    Frame height
    % of optimal
    solutions
    10 40%
    15 21%
    20 6%
    Rotation
    % of optimal
    solutions
    No 19%
    Yes 26%
    Time limit
    (in minutes)
    Average % gap from
    optimal solution
    4 9.8%
    5 8.7%
    6 6.6%
    7 6.7%
    These data are courtesy of the Operations Research groups at Unibo and Unimore.
    Medium-difficulty problem, assigned to everyone
    

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15. Official website
    http://gianlucacosta.info/TwoBinPack
    

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16. Conclusions
    Gnoseological
    results
    Enhanced
    algorithms
    Open source
    framework
    Plugins &
    New apps
    

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17. Special thanks
    ●
    Special thanks, for their valuable advice and
    suggestions, to:
    – Professor Silvano Martello
    – Prof. Manuel Iori
    – Prof. Enrico Malaguti
    – Dr. Maxence Delorme
    

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18. Elegance always matters
    Thanks for your attention! ^__^!
    

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