Instance: p4hd

1. Contents:
2. Information
3. File downloads
4. Solution files
   1. UPIT
   2. CPIT
   3. PCPSP
5. References

Information:

Description:

Gold/Copper mine in Nevada, USA.

Block model:

Block size: 50x50x20 ft.

Precedence computed with 45 degrees using 8 levels

Two destinations: 1 (mill), 2 (waste)

Blockfile columns detail:

<id> <x> <y> <z> <tonn> <blockvalue> <destination> <Au (oz/ton)> <Ag (oz/ton)> <Cu %>

Blockvalue computation:

precomputed by provider.

Type of Constraints:

C0 Capacity constraint (mine): Total extracted tonnage < 52.5M

C1 Capacity constraint (mill): Total processed tonnage < 12.5M

File downloads:

• .blocks file: p4hd.blocks
  
• .prec file: p4hd.prec
• .upit file: p4hd.upit
• .cpit file: p4hd.cpit

Download the Minelib data format specification.

Solution files:

UPIT

Download: p4hd_upit.sol

Objective value: 293,373,256

Computed using Hochbaum's pseudoflow algorithm. [*]

CPIT

Download: p4hd_cpit_gmunoz120723.sol

Objective value: 246,138,696 (LP GAP 0.5%)

Provided by Gonzalo Muñoz, and obtained from the LP relaxation using a modified TopoSort heuristic. [*]

Download: p4hd.LPcpit

LP relaxation solution (not feasible)

Objective value: 247,415,730

Computed using a modified version of Bienstock & Zuckerberg algorithm. [*]

PCPSP

Unable to construct a PCPSP file from the provided information.

References:

• Daniel Bienstock, Mark Zuckerberg (2010), Solving LP Relaxations of Large-Scale Precedence Constrained Problems. IPCO 2010: 1-14
• Dorit S. Hochbaum (2008), The Pseudoflow Algorithm: A New Algorithm for the Maximum-Flow Problem. Operations Research 56(4): 992-1009
  
• Gonzalo Muñoz (2012), Modelos de optimizacion lineal entera y aplicaciones a la mineria. Master thesis, Dept. Mathematical Engineering, Universidad de Chile.