Fully adaptive cross-entropy optimization
Algorithms AIMech:FullyAdaptiveCrossEntropyOptimization DRAFT
A named cross-entropy optimization variant, called FACE in the source, that fixes an elite sample count and adapts the number of sampled candidates within each iteration. The selected description uses the dedicated top-K likelihood fit and the published flowchart for sample growth, parameter-update/reset transitions and heuristic stopping, with inconsistencies in the accompanying numbered pseudocode retained explicitly.
Identity Notes & Concept Scope
Fresh collection at actual merged base c056d16ecdad4e240beaaf5cf04b36d7b34fe052 inspected 754 maintained and 442 pinned AIO identities. Four fixed-string word-boundary searches included ignored and hidden files across all four recorded checkouts, retaining 13,592 occurrences in 773 content groups. Root read all 505 probe-bearing passage sets, all 22 complete candidate-bearing contexts, four complete long HTML scalar lines, all seven normalized context matches, and all 12 selected full frontier objects. All 909 main and 393 nested objects were mechanically queried; this is not a manual read of all frontier bodies. The same-author context assessment supplies exact occurrence reconstruction and dispositions. No competing candidate identity was found within this bounded current collection. Reuse existing owner 245 for the named FACE controller with a fixed elite count and adaptive sample size and bounded stopping heuristics. Generic CrossEntropyOptimization, EDA, PBIL and UMDA do not already encode this full source-scoped controller. Preserve the printed top-K/quantile and flowchart/reset ambiguities rather than claiming one uniquely specified executable algorithm.
Claims & Grounded Evidence
6 Claims
Scope
#named-adaptive-optimization-controller
FACE modifies the tutorial’s cross-entropy optimization procedure by holding the number K of elite sample occurrences fixed while allowing the current sample size N_t to vary. The section heading uses fully adaptive and the text expands FACE as fully automated CE. The selected identity is this named optimization controller, not the fixed-nominal rare-event probability estimator or an assertion that all tuning choices are automated.
Mechanism
#dedicated-top-k-likelihood-fit
For increasingly ordered scores, the dedicated definition selects the K best sampled occurrences E_t, assigns their worst score gamma_t=S_(N_t-K+1), and fits v_t by maximizing sum_{X_i in E_t} log f(X_i;v). Its effective elite fraction is K/N_t. These are unweighted optimization likelihood terms, not fixed-nominal rare-event likelihood ratios. Exactly K occurrences require an explicit boundary-tie selection convention; the stated order statistic requires integers 1<=K<=N_t.
Mechanism
#within-iteration-adaptive-sampling
In the flowchart interpretation, each outer iteration starts at N_min and evaluates candidates under the current search law. It compares the current sample maximum S*_t and worst-elite score gamma_t with their preceding-iteration values. Strict improvement in either permits a parameter update. If neither improves and the equal-score stopping test does not hold, the sample size is increased by one while it is below N_max and the scores are recomputed. S*_t is the maximum of the current iteration’s sample, not a separately defined best-so-far archive.
Mechanism
#flowchart-update-and-reset-transition
Figure 8 sends an improving iteration to a parameter fit, advances t and resets the next iteration’s sample size to N_min. When N_max is reached without either improvement or the equal-score stop, the chart checks repeated capped iterations: if that cap-history stop does not apply, it also fits and advances. This account follows the explicit flowchart and dedicated elite-set definition; it does not assert that every numbered step gives the same complete executable transition.
Scope
#source-named-stagnation-outcomes
The source labels an output reliable when its tested recent maxima satisfy the displayed equality S*_t=...=S*_(t-d). It labels a repeated-capped-sampling outcome without the prescribed improvements unreliable or hard. These are names for heuristic termination branches and reported candidate scores. They do not provide a confidence level, an optimality certificate or a computational-hardness theorem.
Scope
#configured-budget-and-ce-specialization
The procedure still requires choices for the elite count, N_min, N_max, initial search parameter and stopping history. The source provides problem-specific empirical suggestions for these quantities. Adaptive sample allocation and the fixed elite count specialize generic CE optimization; reducing the allocation to a fixed size only matches another CE realization when elite selection, quantile, tie, smoothing and stopping conventions also agree.
⚠️ Curated Limitations & Negative Results
- The dedicated top-K level on PDF p. 35 is S_(N-K+1), but Algorithm 4.1 refers back to Equation 20, whose ceil((1-rho)N) index becomes N-K at rho=K/N. With distinct scores and 1<=K<N, an inclusive threshold at that latter index selects K+1 occurrences; at K=N it gives index zero in one-based notation. Boundary ties add another selection ambiguity. This description retains the dedicated top-K convention and the discrepancy, without claiming to repair an author implementation.
- The flowchart advances the outer iteration and resets its sample size after fitting, whereas numbered Step 4 returns to Step 2 without an explicit new outer sample or iteration advance. Equation 55 compares d+1 indexed maxima although the prose calls them the last d iterations; the cap-history range has a similar inclusive-count convention. Earlier-history initialization and some sampling/recalculation details remain underspecified. The record is a source-scoped mechanism description, not a certified executable reconstruction.
- Finite stagnation or repeated sample-cap exhaustion can occur away from even a local optimum. Under a fixed proposal with improvement probability p in (0,1), an independent budget N_max misses every improving candidate with probability (1-p)^N_max>0; zero support on improvements is a further boundary. These elementary qualifications do not compute the failure probability of an entire adaptive run. Reliable, hard and high-probability improvement language must not be promoted to general guarantees, especially for noisy scores or finite-precision equality tests.
- The fixed elite count must be an integer compatible with N_min and N_max. Suggested proportional elite sizes need a rounding convention; an admissible likelihood maximizer, parameter support, tie ordering and numerical safeguards also require explicit choices. Although alpha is listed among FACE’s supplied parameters, Algorithm 4.1 does not specify a complete smoothing schedule. The separate Section 4.1 performance-weighted CE modification is not a mandatory FACE operation.
- This identity selects the named adaptive CE optimization controller. It does not replace generic CrossEntropyOptimization, the rare-event CE estimator or the full EDA family. Particular unweighted product-distribution fits can overlap with UMDA, and some smoothing steps can overlap with PBIL, without establishing whole-method equivalence. The source’s reduction to fixed-size CE requires matched selection and control conventions; it is not literal equivalence between the conflicting printed indices.
- The retained published 2005 tutorial is the defining evidence here, with Section 4.2 and its flowchart read directly. The earlier manuscript, cited proofs, applications outside the recorded reading scope and author software are not silently imported. Reported timing gains and parameter suggestions are empirical and problem-specific, not universal speed or convergence results. No author-code execution, optimizer run or benchmark reproduction underlies these claims. Historical owner 245 and the dated identity assessment do not assert absence beyond the inspected repository snapshot.
Artificial Intelligence Ontology (AIO) Grounding
Explicit AIO Snapshot Assessment: No Match
Rationale: No inspected AIO target supplies an informative correspondence for this complete non-neural adaptive sampling procedure without adding optional model, task or network requirements. Individual mathematical substeps and possible machine-learning applications do not alone identify the whole algorithm.
Search Scope: Fresh collection at actual merged base c056d16ecdad4e240beaaf5cf04b36d7b34fe052 inspected 754 maintained and 442 pinned AIO identities. Four fixed-string word-boundary searches included ignored and hidden files across all four recorded checkouts, retaining 13,592 occurrences in 773 content groups. Root read all 505 probe-bearing passage sets, all 22 complete candidate-bearing contexts, four complete long HTML scalar lines, all seven normalized context matches, and all 12 selected full frontier objects. All 909 main and 393 nested objects were mechanically queried; this is not a manual read of all frontier bodies. The same-author context assessment supplies exact occurrence reconstruction and dispositions. No competing candidate identity was found within this bounded current collection. The historical scientific assessment examined 14 exact pinned AIO class contexts and 53 incident-edge rows; this current identity pass does not claim a new full ontology reading. Retain those explicit target-specific no-match reasons and the unchanged pinned snapshot. No ontology-wide or source-family saturation is asserted.
| Examined AIO Candidate | Rejection Reason |
|---|---|
AIO:EvolutionaryLLM
|
The exact class denotes a large language model; its related evolutionary-algorithms synonym does not identify a general probability estimator or FACE optimizer. |
AIO:TrainingStrategy
|
Neither fixed-nominal rare-event estimation nor generic FACE search inherently preprocesses or trains a machine-learning model. |
AIO:MachineLearningTask
|
Parametric proposal/search fitting is an internal algorithm operation, not sufficient to equate the whole procedure with the pinned learning-task class. |
AIO:MetaLearning
|
Adaptive sample allocation or likelihood fitting does not inherently use metadata about machine-learning experiments. |
AIO:ActiveLearning
|
Evaluating event/performance scores does not inherently query labels for predictive learning. |
AIO:ReinforcementLearning
|
Policy-learning applications are possible but are not required by these generic procedures; score feedback alone does not establish this task identity. |
AIO:RandomForest
|
No predictive decision-tree ensemble is a mandatory mechanism. |
AIO:EvaluationBias
|
A possible sampling or finite-estimation limitation is not an identity relation to a testing-population/metric bias concept. |
AIO:MarkovChain
|
Neither construction requires target-invariant Markov transition kernels or the pinned network representation. Encoding a stochastic algorithm state as a Markov process is too generic to identify its defining mechanism. |
AIO:MathematicalFunction
|
The pinned class is a generic mathematical rule and is not restricted to scalar inputs or outputs. Mere mathematical describability of the complete adaptive sampling, fitting and termination procedure supplies no sufficiently specific named-rule correspondence at the chosen algorithm scope. |
AIO:BayesianNetwork
|
A particular sampling family may be graphical; no DAG is inherent to the generic algorithm. |
AIO:ProbabilisticGraphicalModel
|
The pinned graph-expressed conditional-dependence task is optional representation, not the whole method. |
AIO:RestrictedBoltzmannMachine
|
No hidden-layer energy model or restricted Boltzmann family is mandatory. |
AIO:ExponentialFunction
|
Exponential densities and optional performance transforms are examples. A mandatory scalar exponential update is not part of either generic construction, unlike the specifically selected xNES/SNES rules. |
Evidence Sources & Primary Literature
1 Source| Source ID | Publication / Document | Type / Access | Reference & Checksum |
|---|---|---|---|
deboer2005
|
Pieter-Tjerk de Boer, Dirk P. Kroese, Shie Mannor, Reuven Y. Rubinstein
|
primary paper
full_text
|
ID: https://people.smp.uq.edu.au/DirkKroese/ps/aortut.pdf
sha256:f68c734c2789…
|
Curation Provenance
Curator: Codex
Method: ai_assisted
Model: GPT-6
Created: 2026-10-15T11:59:01Z
Updated: 2026-10-15T12:14:23Z