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Record W4255492803 · doi:10.1002/net.20061

Exact solution of the centralized network design problem on directed graphs

2005· article· en· W4255492803 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueNetworks · 2005
Typearticle
Languageen
FieldEngineering
TopicVehicle Routing Optimization Methods
Canadian institutionsMcGill UniversityUniversity of Alberta
Fundersnot available
KeywordsColumn generationCutting-plane methodLagrangian relaxationSpanning treeSteiner tree problemMathematical optimizationBranch and boundDirected graphLinear programming relaxationInterior point methodBranch and cutMathematicsRelaxation (psychology)Constraint (computer-aided design)Upper and lower boundsTree (set theory)Point (geometry)Computer scienceLinear programmingInteger programmingCombinatorics

Abstract

fetched live from OpenAlex

Abstract We present a novel exact solution method for the centralized network design problem on directed graphs. The problem is modeled as the well‐known graph theoretic problem: the capacitated directed spanning tree problem. We propose a Lagrangian relaxation where the subproblem is a directed spanning tree with a degree constraint on the root. The master problem has an exponential number of constraints and variables. To solve it, we present a cut‐and‐column generation algorithm based on analytic centers. The latter solves a restricted master problem using a primal analytic center cutting plane method and strengthens the bound by generating columns that correspond to violated primal constraints. The Lagrangian bound is embedded within branch‐and‐bound leading to an interior point branch‐and‐price algorithm with cut generation. We use a dual interior point method to warm start the solution of the restricted master problem both after adding columns and after branching. We present numerical results indicating that the proposed approach outperforms the literature on the directed case. © 2005 Wiley Periodicals, Inc. NETWORKS, Vol. 45(4), 181–192 2005

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: Simulation or modeling
GenreCandidate signal: Methods · Consensus signal: none
Teacher disagreement score0.741
Threshold uncertainty score0.464

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.001
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.016
GPT teacher head0.234
Teacher spread0.218 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it