REVIEW 5 major objections 5 minor 39 references
Performance Analysis of Convolutional Neural Network By Applying Unconstrained Binary Quadratic Programming
T0 review · 5 major / 5 minor · reviewed 2026-08-07 · deepseek-v4-flash
Pith's one-line read Encoding a CNN loss as a QUBO matrix and annealing it yields 10-15% higher MNIST accuracy than back-propagation, at similar runtime.
desk verdict The QUBO encoding in Section III.C.2 is a sample/parameter category error, so the annealer is likely minimizing a different objective and the reported accuracy gains are not meaningful. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The load-bearing object is the QUBO matrix: an objective $y = x^{T}Qx$ over binary variables $x$, constructed from the CNN loss by the coefficient formulas in Section III.C.2. For MSE the bias and coupling terms are $a_i = (2/N)(f(x_i,\theta)-y_i)$ and $b_{ij} = (4/N^2)(f(x_i,\theta)-y_i)(f(x_j,\theta)-y_j)$; for CE they are $a_i = -(1/N)(y_i - f(x_i,\theta))$ and $b_{ij} = -(1/N^2)(y_i - f(x_i,\theta))(y_j - f(x_j,\theta))$. The annealer minimizes this QUBO to choose parameter adjustments, and SGD then updates the weights, replacing the Boltzmann-search step of the CNN-SA pipeline while keeping the classical training loop intact.
What would settle it
Take a fixed set of weights on MNIST, compute both the QUBO energy and the true MSE or CE loss for many candidate binary vectors, and check whether the vector with lowest QUBO energy also has the lowest true loss; if not, the annealer is minimizing a different objective and the reported accuracy gains do not come from the mechanism claimed. A second check is to rerun CNN-QA and CNN-BP from identical initializations and seeds: if the 10-15 percent gap disappears, the headline result is an artifact of comparison conditions.
Extended reading notes
Core claim
The central claim is that inserting quantum annealing after loss computation improves CNN training: the MSE or CE loss is reformulated as a QUBO objective $y = x^{T}Qx$, minimized on an annealer, and the result feeds SGD weight updates. In the 10-fold cross-validation at learning rate 0.1, the CNN-QA model reports higher accuracy than CNN-BP and CNN-SA by roughly 40 percent for MSE and 6 percent for CE, summarized as a 10-15 percent overall improvement at execution times comparable to BP and far below SA. The authors interpret this as QA's binary search over parameter adjustments escaping poor local minima more effectively than gradient-based or thermal search.
Load-bearing premise
The QUBO matrix built from the paper's bias and coupling formulas is assumed to represent the CNN's MSE or CE loss, so that the annealer's minimum is the loss's minimum; this equivalence is asserted, not derived.
Editorial extensions
If this is right
- In 10-fold cross-validation at learning rate 0.1, CNN-QA reports about 40 percent higher accuracy than CNN-BP and CNN-SA for MSE and about 6 percent higher for CE.
- CNN-QA execution times are close to CNN-BP and roughly 2.8 times shorter than CNN-SA, so the accuracy gain is not bought with extra runtime.
- Because only the loss function is annealed, the qubit count stays far below full quantum-gate CNN encodings, making the hybrid approach compatible with current annealer sizes.
- The paper's scaling tests show CNN-QA keeps steady execution time as data size grows, unlike CNN-SA, suggesting the hybrid is the more scalable of the two non-BP optimizers.
- The benefit is objective-dependent: the combinatorial nature of MSE maps more naturally to QUBO than logarithmic CE, so loss choice matters for real deployments.
Reading between the lines
- The QUBO coefficient formulas are presented without a derivation showing that minimizing them is equivalent to minimizing the original MSE or CE loss; until that equivalence is checked, the accuracy gain cannot be confidently attributed to quantum annealing.
- A useful control experiment would run the same QUBO-plus-SGD recipe with a classical QUBO solver; if a classical solver reproduces the accuracy gain, the quantum hardware is not the load-bearing part of the improvement.
- The paper's in-text citation for the QUBO tutorial points to a reference that is not the tutorial named, and the same method is cited elsewhere in the text; readers tracing the derivation should resolve this citation inconsistency first.
- The method should be tested on larger and more varied image datasets and with more loss functions; the authors tested only MNIST with MSE and CE, mostly on a simulator, so the 10-15 percent figure may not transfer.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper proposes a hybrid CNN training method (CNN-QA) that converts MSE or cross-entropy losses into a QUBO matrix (Section III.C.2), optimizes it with D-Wave quantum annealing or its 'neal' simulator, and uses SGD for weight updates. Experiments on MNIST compare CNN-BP, CNN-SA, and CNN-QA under 10-fold cross-validation, 10-epoch, and data-size tests. The paper claims 10--15% accuracy improvement over the baseline with similar execution times, although Section IV.E.1 reports 40% (MSE) and 6% (CE) improvements.
Significance. If a valid QUBO encoding of CNN losses were optimized by quantum annealing with measured gains, this would be a useful contribution to hybrid quantum-classical training. The manuscript makes code available and reports a test on real D-Wave hardware, which is helpful. However, the central equivalence between the QUBO objective and the CNN loss is asserted rather than derived, the CNN-BP-MSE baseline operates at chance level, and the quantitative claims are mutually inconsistent. As presented, the results do not establish the proposed method's validity.
major comments (5)
- [III.C.2] Steps 4–5 define the QUBO bias and coupling coefficients a_i = 2(f(x_i,θ)-y_i)/N and b_ij = 4(f(x_i,θ)-y_i)(f(x_j,θ)-y_j)/N^2 (MSE), with analogous CE terms. These coefficients are functions of the solution variable θ, yet a QUBO matrix must contain constants over the binary variables. The paper gives no derivation connecting sample-indexed residuals to parameter-indexed binary variables, and no such connection exists for a nonlinear network for which f(x,θ) is not linear in the binary encoding of θ. For a single scalar parameter with f(x,θ)=θ, the true MSE is a quadratic in θ, but the proposed coefficients produce a different objective whose minimizer need not coincide with the MSE minimizer. The annealer therefore minimizes an objective that is not shown to be the stated loss, so the claimed accuracy gains cannot be attributed to the proposed QA optimization.
- [IV.E.1 / Figures 8-10] The CNN-BP-MSE baseline runs at approximately 10% accuracy on MNIST (e.g., validity accuracy 0.0986 and test accuracy 0.098 in Figure 8(b); 0.103/0.101 in Figure 9(a); 0.0951/0.0957 in Figure 10(b)). For a 10-class problem, 10% is chance level, indicating a broken or misconfigured baseline. Any relative improvement over such a baseline, including the reported 40% or 10–15%, is not a meaningful measure of the method's performance.
- [Abstract; IV.E.1; Figures 8-10] The reported improvements are mutually inconsistent: the Abstract claims 10–15%; Section IV.E.1 claims 'higher accuracy by 40% for MSE and by 6% for CE'; and the figure data imply roughly 410% relative accuracy gain for MSE (0.0986 to 0.5109) and about 3% relative gain for CE (0.8766 to 0.904). No error bars or variance estimates are provided for any of the curves, so the reader cannot distinguish signal from noise. The central empirical claim needs a single consistent, statistically supported number.
- [V.A] The conclusion's limitation paragraph states that 'the MSE function, aligning with the nature of combinatorial optimization, exhibited superior performance over the logarithmic CE objective function.' All reported data show the opposite: CE accuracies are 0.87–0.92 while MSE accuracies are 0.10–0.52 (e.g., Figures 8–10). This internal contradiction undermines the conclusions drawn about which loss function is compatible with the QA approach.
- [III.C.3; IV.C; IV.D] The experimental section omits essential details for reproducibility: the CNN architecture (number and layout of convolutional and dense layers), the D-Wave 'neal' simulator parameters (number of reads, annealing time, chain strength), the QUBO embedding strategy, and the exact way the QA solution is converted into parameter updates for SGD. Without these, the reader cannot reproduce or assess the validity of the reported accuracy and execution-time results.
minor comments (5)
- [III.C.1] The word 'insymmetric' should be 'in symmetric' (or 'in symmetric form') in the discussion of the Q matrix.
- [IV.B] 'hyprer-parameters' is a typo for 'hyper-parameters'.
- [IV.E.1] The bullet 'around 2.76 times compared to CNN-QA' is unclear; it should specify which method is the reference and which method's time is 2.76 times larger.
- [References / III.C.1] Reference [36] is listed as Nilsson's 'Introduction to machine learning', but the text in Section III.C.1 cites it as the Glover et al. QUBO tutorial; the intended reference is likely [20].
- [II.A.1 / Eq. (2)] Equation (2) is written for binary cross-entropy with a single output; the paper should explain how the CE loss is extended to the 10-class MNIST task.
Circularity Check
The QUBO encoding of the MSE/CE loss is self-referential: the proposed coefficients depend on the parameters the binary variables are supposed to represent, so the annealer minimizes a residual-dependent surrogate rather than the stated loss.
-
self definitional
[Section III.C.1 Eq. (8) and Section III.C.2 steps 2-5]
"QUBO: minimize/maximize y = x^t Q x (8) where x is a vector of binary decision variables and Q is a square matrix of constants. ... Define Bias Terms (a_i): MSE bias terms are defined as: a_i = 2/N (f(x_i, theta)-y_i), and CE bias terms use: a_i = -1/N (y_i - f(x_i, theta))."
Equation (8) requires Q to be a matrix of constants, but the coefficients supplied in steps 4-5 are functions of theta through the residuals f(x_i, theta)-y_i. Steps 2, 6, and 9 state that the binary variables represent the parameters theta, so the QUBO matrix is defined in terms of the same variables it is supposed to determine. No constant Q matrix exists, and the objective minimized by the annealer is not the MSE or CE of Eqs. (9)-(10). The claimed conversion of the loss into QUBO is therefore self-referential: the minimizer appears inside the coefficients of the objective.
full rationale
The empirical comparisons themselves are not circular: the MNIST validation and test accuracies are genuine external measurements rather than fitted predictions, so the accuracy figures have independent content. The circularity lies in the paper's derivation chain that QA minimizes the CNN loss. The paper's own equations define the QUBO coefficients as functions of the residuals f(x_i, theta)-y_i while simultaneously identifying the binary variables with the parameters theta, leaving no fixed Q matrix and no demonstrated equivalence with the MSE/CE objectives. The Note after step 13 and the Conclusion's limitation that CE is 'not inherently compatible with combinatorial optimization' acknowledge that the method's effectiveness is contingent on the objective and the hardware, but they do not repair the missing or self-referential derivation. The self-citations in Section II.B (references [32] and [33], the author's own ResearchGate and StackExchange posts) are used only as motivational community insights and are not load-bearing; the formal QUBO background is cited to the external Glover tutorial. Because the central methodological claim reduces to a residual-dependent surrogate rather than an independent encoding of the loss, while the reported accuracy numbers remain external empirical results, the circularity is partial rather than total.
Assumptions & free parameters
free parameters (3)
- QUBO bias coefficient a_i =
a_i = 2/N (f(x_i,theta) - y_i) for MSE; a_i = -1/N (y_i - f(x_i,theta)) for CE
- QUBO coupling coefficient b_ij =
b_ij = 4/N^2 (f(x_i,theta)-y_i)(f(x_j,theta)-y_j) for MSE; b_ij = -1/N^2 (y_i - f(x_i,theta))(y_j - f(x_j,theta)) for CE
- Learning rate =
0.1 for main results; also 1 and 0.01 in cross-validation
assumptions (3)
- ad hoc to paper The QUBO matrix built from the stated bias and coupling terms is equivalent to the CNN loss (MSE or CE) over the network parameters.
- domain assumption Solving the QUBO via quantum annealing (or its classical simulation) yields a lower-cost solution that improves CNN training when combined with SGD.
- domain assumption Standard CNN training with backpropagation provides a valid baseline for comparison.
Cite this review
Pith. "Pith review of Performance Analysis of Convolutional Neural Network By Applying Unconstrained Binary Quadratic Programming." pith.science (2026). https://pith.science/paper/52LUWP2M
@misc{pith2026250600247,
author = {Pith},
title = {Pith review of: Performance Analysis of Convolutional Neural Network By Applying Unconstrained Binary Quadratic Programming},
year = {2026},
howpublished = {\url{https://pith.science/paper/52LUWP2M}},
note = {Machine review of arXiv:2506.00247}
}
read the original abstract
Convolutional Neural Networks (CNNs) are pivotal in computer vision and Big Data analytics but demand significant computational resources when trained on large-scale datasets. Conventional training via back-propagation (BP) with losses like Mean Squared Error or Cross-Entropy often requires extensive iterations and may converge sub-optimally. Quantum computing offers a promising alternative by leveraging superposition, tunneling, and entanglement to search complex optimization landscapes more efficiently. In this work, we propose a hybrid optimization method that combines an Unconstrained Binary Quadratic Programming (UBQP) formulation with Stochastic Gradient Descent (SGD) to accelerate CNN training. Evaluated on the MNIST dataset, our approach achieves a 10--15\% accuracy improvement over a standard BP-CNN baseline while maintaining similar execution times. These results illustrate the potential of hybrid quantum-classical techniques in High-Performance Computing (HPC) environments for Big Data and Deep Learning. Fully realizing these benefits, however, requires a careful alignment of algorithmic structures with underlying quantum mechanisms.
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Works this paper leans on
-
[1]
Total data volume worldwide 2010-2025,
“Total data volume worldwide 2010-2025,” 2023, accessed on Nov 26,
work page 2010
-
[2]
“Deep Learning,” 2022, accessed on Dec 12, 2022. [Online]. Available: https://mitpress.mit.edu
work page 2022
-
[3]
An Introduction to Convolutional Neural Networks,
K. O’Shea and R. Nash, “An Introduction to Convolutional Neural Networks,” Dec. 2015
work page 2015
-
[4]
Backpropagation Applied to Handwritten Zip Code Recognition,
Y . LeCun, B. Boser, J. S. Denker, D. Henderson, R. E. Howard, W. Hubbard, and L. D. Jackel, “Backpropagation Applied to Handwritten Zip Code Recognition,”Neural Computation, vol. 1, no. 4, pp. 541–551, Dec. 1989
work page 1989
-
[5]
Beyond backpropagation: Using simulated annealing for training neural networks,
R. Sexton, R. Dorsey, and J. Johnson, “Beyond backpropagation: Using simulated annealing for training neural networks,”Journal of End User Computing, vol. 11, 07 1999
work page 1999
-
[6]
Simulated Annealing Algorithm for Deep Learning,
L. M. R. Rere, M. I. Fanany, and A. M. Arymurthy, “Simulated Annealing Algorithm for Deep Learning,”Procedia Computer Science, vol. 72, pp. 137–144, Jan. 2015
work page 2015
-
[7]
T. M. Mitchell,Machine Learning, ser. McGraw-Hill Series in Computer Science. New York: McGraw-Hill, 1997
work page 1997
- [8]
Show all 39 references
-
[9]
Neural Networks and Deep Learning
M. A. Nielsen, “Neural Networks and Deep Learning.” [Online]. Available: http://neuralnetworksanddeeplearning.com
-
[10]
Talbi,Metaheuristics From Design To Implementation
E.-G. Talbi,Metaheuristics From Design To Implementation. University of Lille – CNRS – INRIA, 2009
2009
-
[11]
Optimization by Simulated Annealing,
S. Kirkpatrick, C. D. Gelatt, and M. P. Vecchi, “Optimization by Simulated Annealing,”Science, vol. 220, no. 4598, pp. 671–680, May 1983
1983
-
[12]
Thermodynamical approach to the traveling salesman prob- lem: An efficient simulation algorithm,
V . ˇCern´y, “Thermodynamical approach to the traveling salesman prob- lem: An efficient simulation algorithm,”J Optim Theory Appl, vol. 45, no. 1, pp. 41–51, Jan. 1985
1985
-
[13]
Multivariable Optimization: Quantum Annealing & Computation,
S. Mukherjee and B. K. Chakrabarti, “Multivariable Optimization: Quantum Annealing & Computation,”Eur. Phys. J. Spec. Top., vol. 224, no. 1, pp. 17–24, Feb. 2015
2015
-
[14]
Quantum annealing with manufactured spins,
M. W. Johnson1, M. H. S. Amin1, S. Gildert1, T. Lanting1, F. Hamze1, N. Dickson1, R. Harris1, A. J. Berkley1, J. Johansson2, P. Bunyk1, E. M. Chapple1, C. Enderud1, J. P. Hilton1, K. Karimi1, E. Ladizinsky1, N. Ladizinsky1, T. Oh1, I. Perminov1, C. Rich1, M. C. Thom1, E. Tolka...
2011
-
[15]
Simulated annealing algorithm for deep learning,
L. M. R. Rere, M. I. Fanany, and A. M. Arymurthy, “Simulated annealing algorithm for deep learning,”Procedia Computer Science, vol. 72, 11 2015
2015
-
[16]
Quantum annealing versus classical machine learning applied to a simplified computational biology problem,
R. Y . Li, R. D. Felice, R. Rohs, and D. A. Lidar, “Quantum annealing versus classical machine learning applied to a simplified computational biology problem,”www.nature.com, February 2018
2018
-
[17]
Simulated quantum annealing can be exponentially faster than classical simulated annealing,
E. Crosson and A. W. Harrow, “Simulated quantum annealing can be exponentially faster than classical simulated annealing,”Proc of FOCS 2016, pp. 714-723, June 2016
2016
-
[18]
Goodfellow, Y
I. Goodfellow, Y . Bengio, and A. Courville,Deep Learning. MIT Press, 2016
2016
-
[19]
Nishimori
H. Nishimori. (2015) Nanoscience and quantum physics
2015
-
[20]
A tutorial on formulating QUBO models,
F. W. Glover and Y . D. Gary A. Kochenberger, “A tutorial on formulating QUBO models,”CoRR, vol. abs/1811.11538, 2019
2019 arXiv
-
[21]
A QUBO model for the traveling salesman problem with time windows,
C. Papalitsas, T. Andronikos, K. Giannakis, G. Theocharopoulou, and S. Fanarioti, “A QUBO model for the traveling salesman problem with time windows,”Algorithms, vol. 12, p. 224, 10 2019
2019
-
[22]
Quantum convolutional neural networks,
I. Cong, S. Choi, and M. D. Lukin, “Quantum convolutional neural networks,”Nature Physics, vol. 15, no. 12, p. 1273–1278, Aug 2019
2019
-
[23]
Quantum Neural Network States: A Brief Review of Methods and Applications,
Z.-A. Jia, B. Yi, R. Zhai, Y .-C. Wu, G.-C. Guo, and G.-P. Guo, “Quantum Neural Network States: A Brief Review of Methods and Applications,” vol. 2, no. 7-8, p. 1800077. [Online]. Available: http://arxiv.org/abs/1808.10601
-
[24]
Ascr report on quantum computing for science,
A. Aspuru-Guzik, W. v. Dam, E. Farhi, F. Gaitan, T. Humble, S. Jordan, A. Landahl, P. Love, R. Lucas, J. Preskill, R. Muller, K. Svore, N. Wiebe, and C. Williams, “Ascr report on quantum computing for science,” Cornell University Library, February 2018
2018
-
[25]
Application of quantum annealing to training of deep neural networks,
S. H. Adachi and M. P. Henderson, “Application of quantum annealing to training of deep neural networks,”Cornell University Library, October 2015
2015
-
[26]
A study of complex deep learning networks on high performance, neuromorphic, and quantum computers,
T. E. Potok, C. Schuman, S. R. Young, R. M. Patton, F. Spedalieri, J. Liu, K.-T. Yao, G. Rose, and G. Chakma, “A study of complex deep learning networks on high performance, neuromorphic, and quantum computers,” Cornell University Library, July 2017
2017
-
[27]
An introduction to quantum annealing,
D. d. Falco and D. Tamascelli, “An introduction to quantum annealing,” Thesis, 2011
2011
-
[28]
Quantum algorithms for matrix multiplication and product verification,
R. Kothari and A. Nayak, “Quantum algorithms for matrix multiplication and product verification,”Revised Work of: 2006; Buhrman, Spalek and 2012; Jeffery, Kothari, and Magniez. Link, April 2016
2006
-
[29]
Efficient quantum com- puting simulation through dynamic matrix restructuring and distributed evaluation,
K. S. Aggour, R. M. Mattheyses, and J. Shultz, “Efficient quantum com- puting simulation through dynamic matrix restructuring and distributed evaluation,”Conference paper, October 2007
2007
-
[30]
Ground-state statistics from annealing algorithms: Quantum vs classical approaches,
Y . Matsuda, H. Nishimori, and H. G. Katzgraber, “Ground-state statistics from annealing algorithms: Quantum vs classical approaches,”Research Paper, 2009
2009
-
[31]
Classification with quantum neural networks on near term processors,
E. Farhi and H. Neven, “Classification with quantum neural networks on near term processors,”arXiv-1802.06002, Cornell University Library, 2018
2018 arXiv
-
[32]
Quantum annealing for training convolutional neural net- work?
A. Sharma, “Quantum annealing for training convolutional neural net- work?” 01 2019
2019
-
[33]
Can quantum annealing be used for training convolu- tional neural networks?
A. K. Sharma, “Can quantum annealing be used for training convolu- tional neural networks?” 01 2019
2019
-
[34]
Quantum Annealing vs. QAOA: 127 Qubit Higher-Order Ising Problems on NISQ Computers,
E. Pelofske, A. B ¨artschi, and S. Eidenbenz, “Quantum Annealing vs. QAOA: 127 Qubit Higher-Order Ising Problems on NISQ Computers,” vol. 13948, pp. 240–258, comment: Accepted at ISC HPC 2023. [Online]. Available: http://arxiv.org/abs/2301.00520
2023 arXiv
-
[35]
Lexicalizing linked data for a human friendly web,
R. Perera, P. Nand, W.-H. Yang, and K. Toshioka, “Lexicalizing linked data for a human friendly web,” in2017 7th International Conference on Cloud Computing, Data Science & Engineering - Confluence, pp. 30–35
-
[36]
Introduction to machine learning. an early draft of a proposed textbook,
N. J. Nilsson, “Introduction to machine learning. an early draft of a proposed textbook,” 1996
1996
-
[37]
An introduction to cartan’s kak decomposition for qc programmers,
R. R. Tucci, “An introduction to cartan’s kak decomposition for qc programmers,”Proofs, p. 12, 07 2005
2005
-
[38]
Concept for an algorithm testing and evaluation program at nist,
C. Diaz, “Concept for an algorithm testing and evaluation program at nist,”Proofs, 1994. APPENDIX
1994
-
[2023]
Available: https://www.statista.com/statistics/871513/ worldwide-data-created
[Online]. Available: https://www.statista.com/statistics/871513/ worldwide-data-created
Reviewed August 7, 2026 · model on record in the stance chip above.
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