gmut-76-40

dual-infeasible

The instance

as published

Variables: 24,338
Constraints: 2,398
Nonzeros: 133,435
Format: MPS, gzipped

Where it comes from

provenance

The source instance's LP relaxation is feasible with a bounded optimum. Removing the elements below makes the objective unbounded, and putting any one of them back makes it bounded again.

Rounds run: 565
Bounds dropped: 372
Rows dropped: 188

What was removed

560 entries

lb of x1355_1row AA_94row AA_92lb of x1800_6row AA_205row AA_174row AA_185lb of x3102_6lb of x3096_6lb of x2562_5row AA_176row AA_101

12 of 560 shown. The complete list is in the sidecar.

Also published in the primal-infeasible set view →

Nonzero entries

128 × 128 grid, darker where denser.

Where it sits

Every published instance by size, this one marked. Browse them all.

Download

gmut-76-40_ub.mps.gz0.85 MiB gmut-76-40_ub.meta.json0.12 MiB

The sidecar carries the full provenance, including the fields this page truncates.

Source instance

Namegmut-76-40

Submitted byNora Konnyu

Groupgmu

TermsNo licence of record

Imported from the MIPLIB2010 submissions. It predates MIPLIB's submission form, and the licence that form required. See LICENSE.

set_packingvariable_bound

Timber harvest scheduling model These are harvest scheduling models of hypothetical forest planning problems where net timber revenues are maximized over a planning horizon subject to four sets of constraints: 1. Each management unit can be harvested only once over the planning horizon, 2. Volume harvested in one planning period should not be less or more than some portion of that in the preceding period, 3. Area-weighted average age of the forest by the end of the plan should notbe less than a certain target age. 4. Clearcut size in any planning period has to be below a specific limit. Decision variable are management units and generalized management units (group of management units with a combined area not exceeding the limit on clearcut size) and can be either fully harvested or left untouched in any planning period, therefore there is a binary restriction on the decision variables.

Source description quoted from MIPLIB 2017; links and mathematical notation formatted for the web.

View on MIPLIB 2017 →