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<title-group><article-title>Adaptive Operator Portfolio Population Search for Constrained Engineering Design</article-title></title-group>
<contrib-group>
<contrib contrib-type="author"><name><surname>Park</surname><given-names>Min-Chul</given-names></name><xref ref-type="aff" rid="aff1"/></contrib>
<contrib contrib-type="author"><name><surname>Kim</surname><given-names>Seo-Yeon</given-names></name><xref ref-type="aff" rid="aff1"/></contrib>
<contrib contrib-type="author"><name><surname>Conti</surname><given-names>Alessandro</given-names></name><xref ref-type="aff" rid="aff2"/></contrib>
<contrib contrib-type="author"><name><surname>Hassan</surname><given-names>Samar Q.</given-names></name><xref ref-type="aff" rid="aff3"/></contrib>
<contrib contrib-type="author"><name><surname>Wit</surname><given-names>Pieter J. De</given-names></name><xref ref-type="aff" rid="aff4"/></contrib>
<aff id="aff1">Department of Mechanical Design Engineering, Korea Advanced Institute of Engineering Design (KAIED), Daejeon, Republic of Korea.</aff>
<aff id="aff2">Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy.</aff>
<aff id="aff3">Department of Industrial Engineering, Jordan University of Science and Technology, Irbid, Jordan.</aff>
<aff id="aff4">Department of Mechanical Engineering, KU Leuven, Leuven, Belgium.</aff>
</contrib-group>
<abstract><p>Constrained engineering search can benefit from combining global moves with discrete repair, local feasibility correction and refinement. We study AOPPS, a five-operator population framework with recent-improvement credits and entropy-modulated softmax allocation. The formulation separates admissible-variable repair, penalized comparison and direct feasibility checking, and makes objective-call budgeting explicit. The supplied results describe five engineering test cases and 30 reported runs per case. AOPPS has the lowest displayed mean relative gap on every case. However, the case definitions are abbreviated, the gear-train dimension is inconsistent, the B1 ablation baseline differs from the principal result, and several aggregate statistical outputs require their original input arrays and correction reconstruction. We replace the unsupported finite-population convergence rate with a conditional sublevel-set hitting statement that requires continued feasible search coverage. The contribution is an engineering-oriented operator composition and an inspectable set of reported outcomes; it does not establish improvement below certified optima, universal bandit regret, or verified equal-budget superiority.</p></abstract>
<kwd-group kwd-group-type="author"><kwd>Adaptive operator selection</kwd><kwd>Constrained engineering search</kwd><kwd>Mixed-integer variables</kwd><kwd>Feasibility</kwd></kwd-group>
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<p>assessment, Evaluation budgeting.</p>
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<sec id="sec-2"><label>1</label><title>Introduction</title>
<p>Engineering optimization combines objective improvement with restrictions on stresses, dimensions and admissible manufactured values. Continuous and integer variables can coexist in nonlinear design models <xref ref-type="bibr" rid="ref-1">[1]</xref>, <xref ref-type="bibr" rid="ref-2">[2]</xref>. Constraint handling changes both how candidates are generated and how they are compared. A useful operator portfolio must therefore distinguish a search move, a discrete-domain repair and an attempted feasibility correction. Adaptive operator selection separates credit assignment from the allocation of later trials <xref ref-type="bibr" rid="ref-3">[3]</xref>, <xref ref-type="bibr" rid="ref-4">[4]</xref>. AOPPS places engineering-oriented moves inside such an allocation loop. It uses a small credit table instead of a learned policy network. Neither that choice nor a low-dimensional portfolio establishes that other adaptive schemes ignore constraint structure or are computationally unsuitable without a measured comparison. Finite populations and finite evaluation budgets are practical settings, but an infinite-horizon coverage theorem addresses a different question from performance at a chosen stopping budget. A statement about selecting an operator is also weaker than one about reaching feasible objective sublevel sets. These distinctions determine the scope of the theory below.</p>
<p>Cross-problem comparisons need an explicit estimand. Raw objectives in different engineering units should not be pooled without meaningful normalization. Per-problem relative gaps and rank summaries <xref ref-type="bibr" rid="ref-5">[5]</xref> are useful alternatives, but their reference values, feasibility filters and aggregation units still require definition. Effect sizes <xref ref-type="bibr" rid="ref-6">[6]</xref>, <xref ref-type="bibr" rid="ref-7">[7]</xref> and bootstrap intervals <xref ref-type="bibr" rid="ref-8">[8]</xref> cannot correct a misspecified comparison protocol. The methodological contribution is the composition of perturbation, lattice repair, local constraint correction, SQP refinement and crossover under recent-improvement allocation. The formulation makes temperature safeguards and budget accounting explicit. It does not claim an exact regret theorem for the smoothed softmax rule or that a local projection certifies nonlinear feasibility. The paper first positions this composition, defines the source test cases and comparison rules, and then interprets the supplied results. Numerical observations are preserved while inferential conclusions are limited by the available provenance. Algorithmic consistency corrections are specifications for implementation checking, not records of newly executed experiments. The present claim concerns this particular engineering-oriented portfolio and the five supplied cases. Its distinctive element relative to the companion fold-probing formulation is constraint-aware candidate processing and credit from selected operator attempts, rather than periodic all-operator held-out probes. Shared vocabulary and a softmax controller do not establish independent implementation provenance or a chronology between the manuscripts; those relationships require author disclosure.</p>
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<sec id="sec-3"><label>2</label><title>Background and Related Work</title>
<sec id="sec-4"><label>2.1</label><title>Classical Evolutionary and Swarm Methods</title>
<p>Genetic algorithms <xref ref-type="bibr" rid="ref-9">[9]</xref>, differential evolution <xref ref-type="bibr" rid="ref-10">[10]</xref>, particle swarms <xref ref-type="bibr" rid="ref-11">[11]</xref> and simulated annealing <xref ref-type="bibr" rid="ref-12">[12]</xref> provide different candidate-generation mechanisms. Their basic forms need admissible-variable and constraint-handling rules when applied to engineering models. GWO <xref ref-type="bibr" rid="ref-13">[13]</xref> is a named comparator in the supplied experiment; its presence does not make the comparison exhaustive of current optimization methods.</p>
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<sec id="sec-5"><label>2.2</label><title>Adaptive and Self-Adaptive Variants</title>
<p>SHADE <xref ref-type="bibr" rid="ref-14">[14]</xref> adapts differential-evolution parameters from successful trials, while L-SHADE <xref ref-type="bibr" rid="ref-15">[15]</xref> adds population-size reduction. Subsequent mutation and hybrid variants <xref ref-type="bibr" rid="ref-16">[16]</xref> broaden this design space. Parameter adaptation and operator selection are related but distinct mechanisms; their performance depends on the specific executed variant. Covariance-adaptation methods <xref ref-type="bibr" rid="ref-17">[17]</xref> form a separate stateful comparison family. Hyper-heuristics <xref ref-type="bibr" rid="ref-18">[18]</xref> and adaptive operator selection <xref ref-type="bibr" rid="ref-3">[3]</xref>, <xref ref-type="bibr" rid="ref-4">[4]</xref> already study online allocation among heuristics. AOPPS is positioned as a concrete engineering-oriented composition rather than the first framework to use structure-aware search. Automatic configuration through irace <xref ref-type="bibr" rid="ref-19">[19]</xref> can support such comparisons only when configurations and development costs are recorded.</p>
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<sec id="sec-6"><label>2.3</label><title>Adaptive Operator Selection as a Bandit Problem</title>
<p>The AOPPS credit is a normalized recent improvement from a selected operator attempt. A softmax distribution then allocates future attempts. This admits a bandit interpretation at the level of action selection <xref ref-type="bibr" rid="ref-20">[20–22]</xref>, but the operator rewards depend on the evolving population and constraint state; they are not stationary independent arm rewards. The cited bandit literature <xref ref-type="bibr" rid="ref-20">[20]</xref>, <xref ref-type="bibr" rid="ref-21">[21]</xref> proves guarantees for specified policies and assumptions. It does not supply an O(√(K log K/T)) regret rate for an arbitrary fixed-forgetting-factor, entropy-modulated softmax. No such rate is claimed for AOPPS. Logged credits can describe adaptation, but do not identify a phase-optimal policy without counterfactual operator comparisons.</p>
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<sec id="sec-7"><label>2.4</label><title>Engineering-Design Benchmarks</title>
<p>Welded-beam, pressure-vessel, spring and speed-reducer models are useful engineering test cases <xref ref-type="bibr" rid="ref-1">[1]</xref>, <xref ref-type="bibr" rid="ref-2">[2]</xref>. Their multiple published formulations can differ in bounds, admissible thicknesses, coil counts and constraint conventions. The source labels and reference values must therefore be tied to complete equations before feasibility and optimality claims are reproducible. These analytic test cases do not reproduce simulator cost, manufacturing tolerances or the full validation requirements of deployed engineering designs. They are used here as reported optimization cases. A small reference-relative gap does not certify an implementable or safe physical design.</p>
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<sec id="sec-8"><label>2.5</label><title>Positioning of the Proposed Work</title>
<p>AOPPS combines a local constraint-correction attempt with perturbation, discrete repair, refinement and crossover. Its evaluation question is whether this composition improves feasible outcomes under a fully counted objective-call budget. The supplied tables provide descriptive evidence, while the incomplete case specifications, tuning provenance and statistical inputs prevent a verified novelty or superiority certificate.</p>
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</sec>
<sec id="sec-9"><label>3</label><title>Problem Formulation</title>
<p>We consider a constrained mixed-integer nonlinear program of the form</p>
<p>min f(x, z) s.t. g_i(x, z) ≤ 0, i = 1,…,m; x ∈ [x_L, x_U] ⊂ ℝⁿ, z ∈ ⊂ ℤᵖ, (1)</p>
<p>The continuous vector x represents geometric dimensions and z indexes admissible integer values. Integer variables such as gear teeth are ordered lattice quantities, not automatically nominal categories. A thickness can be represented as an integer index times a specified manufacturing increment. Arbitrary categorical choices require a separate encoding and move definition. The source compares candidates using a changing penalized score:</p>
<p>F_t(x, z) = f(x, z) + λ(t) · Σ_i max(0, g_i(x, z))², λ(t) = λ₀ · (1 + γ · t/T). (2)</p>
<p>When f and all g_i are continuously differentiable, squared positive-part penalties are continuously differentiable; this does not follow from differentiability of f alone. The finite schedule increases λ from λ₀ to λ₀(1+γ), so it does not diverge over the configured horizon. It discourages violations without guaranteeing feasibility. Local linearized projections must be followed by evaluation of the original nonlinear constraints. Define r(x,z)=|f(x,z)−f_ref|/max(|f_ref|,ε), ε=10⁻⁸, using a supplied reference f_ref. <xref ref-type="table" rid="tab2">Table 2</xref> reports 100r in percentage units. An absolute gap does not distinguish values above and below the reference, and a reference need not be a certified optimum. Feasibility must be reported separately through V(x,z)=Σ_i max{0,g_i(x,z)} and the specified tolerances, rather than inferred from r. Every generated candidate must be mapped to admissible bounds and integer increments, regardless of which operator produced it. Constraint units and scaling must be stated before combining squared violations in one penalty. A local correction based on constraint normals may reduce a linearized violation while leaving nonlinear constraints unsatisfied.</p>
<sec id="sec-10"><label>3.1</label><title>Welded-Beam Design (B1)</title>
<p>B1 is reported as a four-variable welded-beam cost model, f=1.10471h²L+0.04811tb(14+L), with five constraints and reference 1.724852. The abbreviated description supplies nominal bounds 0.1–10.0 but not the full stress, deflection, buckling and geometric equations. These missing details must be supplied before the reference can be matched to the executed variant.</p>
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<sec id="sec-11"><label>3.2</label><title>Pressure-Vessel Design (B2)</title>
<p>B2 is reported as pressure-vessel cost minimization in shell thickness, head thickness, radius and cylinder length. Thicknesses are multiples of 0.0625 inch, so a continuous move must be mapped back to admissible thickness indices. The source reference is 5885.3327. Complete bounds, volume and thickness constraints, tolerance conventions and returned vectors are needed to validate feasible comparisons.</p>
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<sec id="sec-12"><label>3.3</label><title>Tension–Compression Spring Design (B3)</title>
<p>B3 is a three-variable spring-volume case with wire diameter, coil diameter and a continuous active-coil count, four reported constraints and reference 0.012665. Treating coil count as continuous defines a relaxation of a manufactured integer-coil design. The result therefore applies only to the executed relaxation unless an integer design and its feasibility are separately established.</p>
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<sec id="sec-13"><label>3.4</label><title>Speed-Reducer Design (B4)</title>
<p>B4 is a seven-variable speed-reducer case with eleven reported constraints and reference 2994.4207. The description includes a tooth-count variable alongside continuous shaft and gear dimensions. The full objective, bounds and constraint equations remain necessary to reproduce the source outcomes.</p>
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<sec id="sec-14"><label>3.5</label><title>Planetary Gear-Train Design (B5)</title>
<p>B5 is unresolved at the model-definition level. The prose names four tooth-count variables despite saying three, while <xref ref-type="table" rid="tab1">Table 1</xref> reports dimension six. It gives target ratio 4.611, integer bounds <xref ref-type="bibr" rid="ref-5">[5]</xref> and reference 1.49×10⁻⁷, but not the ratio formula or a six-variable mapping. We retain the reported numerical results without inventing the two missing variables or asserting that they correspond to a standard planetary-gear benchmark.</p>
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<sec id="sec-15"><label>4</label><title>Proposed Approach: AOPPS</title>
<sec id="sec-16"><label>4.1</label><title>Algorithm Overview</title>
<p>AOPPS maintains N evaluated candidates and a global K=5 credit table. Candidate generation, admissible-variable repair and nonlinear feasibility checking are separate steps. Entropy modulates allocation temperature; the reported feasibility rate is a diagnostic unless an explicit control dependence is specified. The global credit table uses recent outcomes without fitting a neural policy. Its overhead is small in K, but its total cost depends on the selected operators. SQP iterations, derivative estimates and constraint-correction trials may consume multiple objective calls for one population member and must be counted.</p>
<fig id="fig1"><label>Figure 1</label><caption><p>Original pipeline schematic retained from the source.</p></caption><graphic xlink:href="https://opt.reapress.com/public/journals/1/jats-figures/126/fig-1-b4d5ea7ad431.png"/></fig>
<p>Its theorem inset is not a verified convergence result; the conditional statement and required safeguards are given in Section 4.5. The schematic does not establish the exact executed operator dictionary or state updates.</p>
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<sec id="sec-17"><label>4.2</label><title>Domain-Specific Operator Portfolio</title>
<p>The source portfolio contains a heavy-tailed perturbation, integer-increment repair, local feasibility correction, up to five SQP steps, and arithmetic crossover. Integer repair and bound clipping are mandatory admissibility operations after every move, even when also available as a selectable operator. The local correction uses constraint normals but cannot certify nonlinear feasibility.</p>
<p>SQP applies to differentiable continuous subproblems with discrete coordinates fixed; numerical derivative calls consume budget. Crossover needs an explicit discrete inheritance rule. The five labels describe intended roles. Heavy tails do not prove escape from every basin, rounding does not enforce nonlinear constraints, and an arithmetic blend of feasible points need not remain feasible in a nonconvex region. Claims about extra operators or preliminary diminishing returns require their omitted experimental outputs.</p>
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<sec id="sec-18"><label>4.3</label><title>Adaptive Operator Selection: A Decayed Bandit View</title>
<p>Let the population entropy at iteration t be defined as</p>
<p>H_t = − Σ_b p_b(t) · log p_b(t), (3)</p>
<p>Here p_b(t) is the fraction of candidates in bin b of a specified projected histogram. Binning, scaling and the projection basis must be documented; a moving principal-component basis can change entropy without a change in global reachability. Lower entropy lowers the source temperature and concentrates allocation toward higher-credit operators, rather than selectively increasing exploration.</p>
<p>Pr(op = k | t, i) = exp(Q_k(t)/τ_t) / Σ_{k&apos;} exp(Q_{k&apos;}(t)/τ_t), (4)</p>
<p>The source schedule τ_t=τ₀H_t/H₀ is undefined if H₀=0 and singular if H_t=0. A well-defined implementation requires positive denominator and temperature safeguards, for example τ_t=max{τ_min,τ₀H_t/max(H₀,h_min)} with τ_min,h_min&gt;0. This is a consistency specification whose execution must be checked against source code. No fixed lower operator-probability bound follows from the unsafeguarded schedule.</p>
<p>Q_k(t+1) = (1 − η) · Q_k(t) + η · ΔF_k(t), (5)</p>
<p>For an operator attempt at a fixed t, compare parent and offspring using the same F_t. A well-defined credit is max{0,F_t(parent)−F_t(offspring)}/max(m_t,m_min), where m_t is the recorded median absolute improvement over the last 50 iterations and m_min&gt;0. Each selected operator must receive an update for the attempt, including zero improvement, if the credit is intended to estimate average attempt utility. Multiple attempts require a stated update order; the other credit components remain unchanged.</p>
<p>Eq. (5) is recency-weighted reward estimation followed by Boltzmann allocation <xref ref-type="bibr" rid="ref-21">[21]</xref>. It is not an exact equivalence to a policy with a transferable generic regret bound. A decreasing temperature increases exploitation; bounded rewards and positive temperature alone do not establish useful candidate coverage or finite-time optimization rates.</p>
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<sec id="sec-19"><label>4.4</label><title>Pseudocode</title>
<p>Algorithm 1. AOPPS.</p>
<p>Input: N candidates, generation cap T, hard new-objective-call budget B, operators and constraints.</p>
<p>Output: best evaluated feasible design if one exists; otherwise report no feasible incumbent.</p>
<p>1. Initialize exactly N admissible candidates; evaluate objectives and constraints, and count every call.</p>
<p>2. Set Q_k=0; initialize a feasible incumbent and the stated histogram/credit history.</p>
<p>3. For t=1,…,T while budget remains:</p>
<p>4. Compute the specified entropy and report the feasibility rate.</p>
<p>5. Update a positive safeguarded temperature; confirm the executed safeguards.</p>
<p>6. Set λ(t) and compare all candidates using scores at this same t.</p>
<p>7. For each budget-permitted candidate attempt:</p>
<p>8. Sample operator k using Eq. (4).</p>
<p>9. Generate an offspring, holding integer coordinates fixed during continuous SQP.</p>
<p>10. Repair bounds and integer increments; apply the specified local correction policy.</p>
<p>11. Evaluate the original objective and constraints; count derivative and repair trials.</p>
<p>12. Calculate pre-replacement reward and update selected credit, including unsuccessful attempts.</p>
<p>13. Accept under the stated same-time score rule; retain any improved feasible incumbent.</p>
<p>14. End candidate loop.</p>
<p>15. Apply the recorded stagnation rule, reporting actual evaluations if stopped early.</p>
<p>16. End generation loop at T or the hard budget B.</p>
<p>17. Return the feasible incumbent and all residual violations, or a feasibility-failure status.</p>
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<sec id="sec-20"><label>4.5</label><title>Complexity and Convergence</title>
<p>For an objective-call cost C_f, vector operations for a population cycle can be O(Nd), and allocation uses O(NK). Local projections and SQP may require Jacobians, linear or quadratic subproblem solves and several calls, so they are not generally O(d). With N=50 and T=1,000, a single call per particle per cycle would already require 50,000 calls, exceeding the reported B=20,000. The hard call counter must therefore control execution independently of the generation cap. A coverage result needs assumptions about feasible candidate proposals, not merely compactness, bounded rewards, operator-label selection or ergodicity of discrete coordinates. Assume exact evaluations of one fixed original objective and a finite value f★=inf of the original objective on the feasible mixed domain, and let Aε be its feasible ε-sublevel set. Suppose an elitist feasible incumbent is retained and each eligible proposal trial has conditional probability at least qε&gt;0 of producing a point in Aε. Proposition 1 (conditional hitting). After m such trials, the probability that the best feasible incumbent has not reached Aε satisfies</p>
<p>Pr(best_m&gt;f★+ε, or no feasible incumbent) ≤ (1−qε)^m. (6)</p>
<p>Repeated conditional expectation bounds consecutive miss probabilities by their product; after a hit, the feasible incumbent is retained. If eligible trials continue indefinitely for every ε&gt;0, objective values approach f★ almost surely. A positive-temperature softmax over operators and discrete rounding do not establish the required probability on continuous feasible sublevel sets, especially with equality constraints or zero-volume feasible sets. The finite stopping rule, bounded penalty and source outputs do not verify these assumptions, and no Hoeffding objective-error rate is claimed.</p>
</sec>
</sec>
<sec id="sec-21"><label>5</label><title>Experimental Setup</title>
<p>The source reports five cases, 30 runs each and a limit of 20,000 penalized-fitness evaluations. Comparator labels are GA <xref ref-type="bibr" rid="ref-9">[9]</xref>, DE <xref ref-type="bibr" rid="ref-10">[10]</xref>, SA <xref ref-type="bibr" rid="ref-12">[12]</xref>, PSO <xref ref-type="bibr" rid="ref-11">[11]</xref> and GWO <xref ref-type="bibr" rid="ref-13">[13]</xref>. It describes irace <xref ref-type="bibr" rid="ref-19">[19]</xref> tuning with 1,000 evaluations and different random seeds. A different seed is not a disjoint validation problem set. Exact scenarios, configurations and all development costs are required to assess the fairness of the tuning protocol. “Mixed” denotes continuous and integer variables; the B5 dimension and missing equations require author reconciliation. Reported defaults are N=50, T=1,000, τ₀=1.0, η=0.10, p_levy=0.10, λ₀=0.5 and γ=2.0. They were reportedly selected by a coarse B1 sweep, making B1 a development case included in the result set. The absence of per-case retuning does not make that case independent test evidence. The source reports NumPy 1.26, SciPy 1.14 and scipy.optimize.SLSQP on an Intel i7-12700 system. Its seed expression MD5(algorithm||case||run_index) includes the algorithm name and therefore produces algorithm-specific seeds; it does not establish common initial populations or matched random streams. Implementation files and logs are absent. The stated 0.4 Wh and 0.38 kg CO₂e/kWh imply approximately 0.152 g CO₂e per run arithmetically, but measured energy and grid provenance are not supplied. The descriptive unit is a run within a case. A problem-block Friedman analysis across five cases is distinct from pooling 150 run differences across heterogeneous cases. <xref ref-type="table" rid="tab3">Table 3</xref> contains five aggregate contrasts, whereas the prose mentions families of 25 and 75 tests. The paired observations, zero/tie conventions, family definition and resampling units must be supplied before inferential claims are made <xref ref-type="bibr" rid="ref-5">[5-8]</xref>.</p>
<table-wrap id="tab1"><label>Table 1</label><caption><p>Supplied case characteristics and reference values.</p></caption><graphic content-type="pdf-region" xlink:href="pdf-region:6:66,673.3,537.1,757.6"/><p content-type="note">This table is shown in the PDF version of the article.</p></table-wrap>
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<sec id="sec-22"><label>6</label><title>Results and Statistical Analysis</title>
<sec id="sec-23"><label>6.1</label><title>Convergence Behaviour</title>
<p>The original B1 plot is retained but cannot presently be interpreted as a fixed-objective best-so-far feasible trace. Its median rises near the annotated SQP transition, which an elitist fixed-objective incumbent cannot do. Its endpoint also differs from the principal B1 summary. A changing penalty score, current candidate or another campaign would be a different quantity; the raw trace must identify which was plotted. The source’s phase annotations describe an intended exploration-to-refinement interpretation. They do not establish that a component caused the depicted changes or that the same phases occurred on other cases. Iteration counts also do not provide equal objective-call locations when selected operators have different costs.</p>
<fig id="fig2"><label>Figure 2</label><caption><p>Original source B1 trace.</p></caption><graphic xlink:href="https://opt.reapress.com/public/journals/1/jats-figures/126/fig-2-5aa0451a41de.png"/></fig>
<p>The labelled best-so-far median is nonmonotone near the SQP transition and its endpoint is not reconciled with <xref ref-type="table" rid="tab2">Table 2</xref>. The plotted quantity, campaign and interval inputs require confirmation; no convergence certificate is inferred.</p>
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<sec id="sec-24"><label>6.2</label><title>Operator-Portfolio Usage Evolution</title>
<p>The original probability plot describes reported shifts among operator labels. A high selected share indicates allocation by the controller, not that the operator is optimal at that stage. Demonstrating tracking of the best operator would require contemporaneous counterfactual evaluations or a defined reference policy. Aggregated selection profiles can hide variation across runs. Credit initialization, histogram definition and zero-improvement updates must be supplied to attribute the plotted profile to the stated recurrence. The plot does not independently verify causal roles of perturbation, projection, crossover or SQP.</p>
<fig id="fig3"><label>Figure 3</label><caption><p>Original source allocation profile, averaged as reported.</p></caption><graphic xlink:href="https://opt.reapress.com/public/journals/1/jats-figures/126/fig-3-7230d5b10933.png"/></fig>
<p>Selection logs and the implemented credit/temperature update are required to verify its relationship to Eqs. (4) and (5).</p>
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<sec id="sec-25"><label>6.3</label><title>Comparative Performance and Rank Statistics</title>
<p>AOPPS has the lowest displayed mean relative gap on all five cases in <xref ref-type="table" rid="tab2">Table 2</xref>. The supplied mean ranks give AOPPS 1.02, but their aggregation differs from simply ranking the displayed case means. Conditional on the reported CD=3.37, the differences from GA (4.14) and SA (4.77) exceed the threshold; differences from DE, GWO and PSO do not. This corrects the broader claim attached to the source abstract. The source Friedman statistic and p-value require the rank matrix. <xref ref-type="table" rid="tab3">Table 3</xref>’s very small aggregate p-values do not establish all 25 per-case contrasts. Its displayed Holm entries also fail the step-down monotonicity requirement for the stated family when applied to the displayed raw p-values. Rebuilding the analysis requires original differences with their case/run mapping; a pooled sample count of 150 does not create 150 independent benchmark problems.</p>
<table-wrap id="tab2"><label>Table 2</label><caption><p>Supplied mean relative gaps in percentage units and standard deviations for 30 reported runs per case, with source mean-rank summaries.</p></caption><graphic content-type="pdf-region" xlink:href="pdf-region:7:66,139.4,537.1,231"/><p content-type="note">This table is shown in the PDF version of the article.</p></table-wrap>
<p>Feasibility, case equations and aggregation require verification.</p>
<table-wrap id="tab3"><label>Table 3</label><caption><p>Five source-reported aggregate signed-rank contrasts. All numbers are retained; pairing, cross-case aggregation and Holm correction are unresolved.</p></caption><graphic content-type="pdf-region" xlink:href="pdf-region:8:66,661.3,537.1,744.7"/><p content-type="note">This table is shown in the PDF version of the article.</p></table-wrap>
<fig id="fig4"><label>Figure 4</label><caption><p>Original mean-rank and critical-difference illustration.</p></caption><graphic xlink:href="https://opt.reapress.com/public/journals/1/jats-figures/126/fig-4-4b38aebc39c8.png"/></fig>
<p>Using its source CD=3.37, AOPPS exceeds the threshold only against GA and SA. This conditional reading is not a reconstruction of the test inputs.</p>
</sec>
<sec id="sec-26"><label>6.4</label><title>Effect-Size and Bootstrap Confidence Intervals</title>
<p><xref ref-type="table" rid="tab4">Table 4</xref> retains source effect sizes and intervals. Cliff’s δ <xref ref-type="bibr" rid="ref-6">[6]</xref> measures ordering of the defined outcomes, and Hedges’ g <xref ref-type="bibr" rid="ref-7">[7]</xref> standardizes a difference with a small-sample correction. Their strongly negative values favor AOPPS under the stated difference direction, but require the actual feasible-outcome arrays. Threshold labels and nonzero intervals are conditional descriptions, not validation of missing case definitions or the pooling design. Averaging standardized effects across only five cases is a descriptive summary whose weighting and uncertainty must be justified. It does not establish a general advantage over an engineering-problem population or demonstrate that the controller caused the observed gaps.</p>
<table-wrap id="tab4"><label>Table 4</label><caption><p>Source effect sizes and reported BCa intervals.</p></caption><graphic content-type="pdf-region" xlink:href="pdf-region:8:66,59.7,537.1,267.7"/><graphic content-type="pdf-region" xlink:href="pdf-region:9:66,605.1,537.1,758.9"/><p content-type="note">This table is shown in the PDF version of the article.</p></table-wrap>
<p>Mean differences and interval limits are in relative-gap ratio units, whereas <xref ref-type="table" rid="tab2">Table 2</xref> uses percentages. Negative differences favor AOPPS; raw arrays and resampling provenance are required.</p>
</sec>
<sec id="sec-27"><label>6.5</label><title>Per-Problem Rank Heatmap</title>
<p>The heatmap supplies reported case-level ranks. It must be tied to either per-run rankings or ranks of case means; these are different summaries. Favorable displayed ordering across five cases motivates further evaluation without establishing generalization to unseen engineering models.</p>
<fig id="fig5"><label>Figure 5</label><caption><p>Original reported case-level rank heatmap; the rank matrix and aggregation rule require confirmation.</p></caption><graphic xlink:href="https://opt.reapress.com/public/journals/1/jats-figures/126/fig-5-1d8b1a63185b.png"/></fig>
</sec>
<sec id="sec-28"><label>6.6</label><title>Morris Sensitivity Analysis</title>
<p>Morris <xref ref-type="bibr" rid="ref-23">[23]</xref> screening uses elementary effects over specified parameter ranges and a defined response. The source reports 30 trajectories and four levels and ranks λ₀ and N highest by mean absolute effect. Those rankings are conditional on the ranges, normalization and response. A nonzero dispersion can arise from nonlinearity or interaction and does not separate them.</p>
<p>Low elementary effects within sampled ranges do not establish transferable safe defaults or low sensitivity outside those ranges. The design matrix, response definition, repeated-run aggregation and uncertainty are needed to reproduce the reported screening and compare integer parameters with continuous ones.</p>
<fig id="fig6"><label>Figure 6</label><caption><p>Original reported Morris estimates.</p></caption><graphic xlink:href="https://opt.reapress.com/public/journals/1/jats-figures/126/fig-6-fe4b9abfd2a0.png"/></fig>
<p>Parameter ranges, normalized steps and response construction are unresolved; the plot does not certify robust deployment settings.</p>
</sec>
<sec id="sec-29"><label>6.7</label><title>Ablation Study</title>
<p><xref ref-type="table" rid="tab5">Table 5</xref>’s full B1 mean is 0.04%, while <xref ref-type="table" rid="tab2">Table 2</xref> reports 4.54% for B1. This unresolved campaign or metric discrepancy prevents treating the ablation as a decomposition of the principal result. Arithmetic relative to the displayed 0.04 baseline gives increases of 875% for uniform allocation, 2,550% without projection, 750% without SQP, 350% without Lévy perturbation and 200% without crossover. These correct the prose’s smaller percentages but do not validate the ablation data. Projection removal has the largest displayed ablation gap. Its magnitude exceeds the increase under uniform allocation, contradicting the claim that every individual removal hurts less than disabling adaptation. Equal call budgets, actual residual violations and unchanged remaining settings are required for causal interpretation. The supplied interval bounds are retained, but their scale and estimand do not reconcile with the displayed percentage changes.</p>
<table-wrap id="tab5"><label>Table 5</label><caption><p>Supplied B1 ablation means, degradation entries and interval bounds.</p></caption><graphic content-type="pdf-region" xlink:href="pdf-region:10:66,65.6,537.1,280"/><p content-type="note">This table is shown in the PDF version of the article.</p></table-wrap>
<p>The principal-result baseline and interval definition require reconciliation; no new ablation was executed.</p>
</sec>
<sec id="sec-30"><label>6.8</label><title>Scalability</title>
<p>The supplied timing increases from 12.3 s at D=30 to 489.7 s at D=200, a factor of approximately 39.8; dimension increases by approximately 6.7. The gap changes from 0.04% to 0.21%, a factor of 5.25. These are endpoint arithmetic, not a proved asymptotic scaling law. The claimed replication by D/4 is not an integer number of four-variable units at D=30, so the generator and reference scaling must be supplied.</p>
<table-wrap id="tab6"><label>Table 6</label><caption><p>Source scalability timings and gaps for reported dimensions and 20,000 evaluations.</p></caption><graphic content-type="pdf-region" xlink:href="pdf-region:11:66,570.6,537.1,656.9"/><p content-type="note">This table is shown in the PDF version of the article.</p></table-wrap>
<p>The replicated-case generator, evaluation accounting and timing protocol require confirmation.</p>
</sec>
</sec>
<sec id="sec-31"><label>7</label><title>Discussion</title>
<p>The source results motivate investigating a combined portfolio, but do not isolate switching as the principal cause of its performance. The ablation’s largest displayed loss occurs without projection, and its baseline differs from the principal B1 experiment. Component conclusions must therefore remain conditional on reconciliation.</p>
<p>A local constraint-aware move is scientifically plausible because it uses information absent from a scalar penalty. Its utility nevertheless depends on Jacobian quality, admissibility and the residual nonlinear violation after correction. The current tables do not supply those quantities or demonstrate a globally feasible projection.</p>
<p>The temperature schedule sharpens allocation as the source entropy declines, subject to explicit safeguards. No supplied constant-temperature comparison supports a numerical rank benefit. Moreover, a lower rank is better, so a stated rank reduction cannot be described as performance degradation without clarifying the comparison direction.</p>
<p>Recent-improvement credits offer a descriptive controller state. They do not import a generic bandit regret guarantee <xref ref-type="bibr" rid="ref-22">[22]</xref>, establish a phase-optimal operator or prove an optimization rate. The current evidence covers five abbreviated analytic cases and does not test simulator noise or manufacturing validation.</p>
</sec>
<sec id="sec-32"><label>8</label><title>Threats to Validity and Counterarguments</title>
<p>Transfer to another engineering class may require different candidate encoding and correction operators. Morris screening does not select or validate an operator library, and low sampled sensitivity does not resolve external validity. A new domain requires its own objective, constraints, tolerances and test protocol.</p>
<p>The bounded penalty in Eq. (2) does not diverge over the configured horizon, and small source gaps do not numerically verify penalty divergence or constrained-optimum recovery. The conditional hitting proposition concerns the original objective on feasible points with an elitist feasible incumbent, requiring a coverage assumption not demonstrated for this implementation.</p>
<p>Tuning bias remains unresolved because B1 helped set AOPPS defaults and the baseline “validation split” is described only through different seeds. Comparator versions, configuration spaces, tuning outcomes and development budgets must be disclosed. Further comparisons with specialized adaptive DE and covariance methods would test a broader claim.</p>
<p>SQP and constraint-normal corrections require well-defined differentiable models or reliable numerical approximations. No execution record demonstrates automatic gating under noisy simulators. Such gating and noisy-regime performance are future validation topics rather than established behavior.</p>
<p>The reported defaults are development choices, not parameters certified across domains. Source sensitivity figures suggest priorities for examination within their unknown tested ranges, but cannot establish robust settings until the design and response are supplied.</p>
<p>Small reported p-values and large effect sizes do not answer missing-data, model-definition, pairing or pooling concerns. Inferential publication requires complete case formulas and feasible vectors, raw outcomes, algorithm and tuning records, correction reconstruction and the source plot/ablation provenance.</p>
</sec>
<sec id="sec-33"><label>9</label><title>Conclusion and Future Work</title>
<p>AOPPS provides an engineering-oriented composition of five operator roles with recent-improvement softmax allocation. The supplied main table favors it descriptively on five cases. The corrected formulation distinguishes lattice admissibility, nonlinear feasibility and bounded penalties, and imposes a hard evaluation counter alongside the generation cap. Its asymptotic coverage statement is conditional and does not certify the finite implementation. Reconciled case definitions, source outputs and statistical inputs are required before stronger comparative or constrained-optimum claims are made.</p>
<p>The next empirical step is release and reconstruction of the existing campaign, followed by independent evaluation on fully specified unseen cases. Multi-objective and surrogate-assisted variants may be useful extensions once their feasibility, credit and budget rules are explicitly validated.</p>
</sec>
<sec id="sec-34"><title>Data and Code Availability</title>
<p>The implementation, raw run outcomes, configurations and sensitivity inputs are not verified in the supplied materials. Authors must disclose the relationship to the companion fold-probing manuscript, including any shared code or observations, without asserting prior acceptance or an unsupported development chronology.</p>
</sec>
</body>
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