TY - M-10422 AU - Gotur, Goutam AU - S, Chaitrashree AU - Saravana Kumar, Dr. TI - A Linear Algebra–Based Mathematical Model of Digital System Performance Using Neural Networks as Predictive Approximators T2 - Scientific Research Journal of Science, Engineering and Technology PY - 2026 VL - 4 IS - 1 SN - 2584-0584 AB - Modern digital systems exhibit complex performance characteristics, throughput, and tail latency that depend nonlinearly on workload features and resource constraints. Traditional linear models 𝐴π‘₯ provide computational efficiency and interpretability but systematically underfit nonlinear phenomena such as cache thrashing, queueing saturation, and inter-resource contention, while black-box neural networks achieve superior accuracy through universal approximation but sacrifice causal interpretability and increase inference latency. This paper develops a hybrid framework decomposing performance prediction into an interpretable linear baseline plus compact neural residual: 𝑦(π‘₯) = 𝐴π‘₯ + 𝑓 (π‘₯; πœƒ), where matrix 𝐴 ∈ β„π‘šΓ—π‘› encodes resource-to-metric contributions and feedforward network 𝑓 (1-3 layers, 32-256 neurons) learns systematic residuals π‘Ÿ(π‘₯) = 𝑓(π‘₯) βˆ’ 𝐴π‘₯. Construction employs ridge regression or sparse optimization for 𝐴, staged training alternating between baseline initialization and residual learning, and complexity analysis showing 𝑂(nnz(𝐴)) + 𝑂(βˆ‘π‘‘β„“βˆ’1𝑑ℓ) inference cost. Across CPU scheduling and bandwidth prediction case studies, the hybrid achieves near-black-box accuracy (MSE: 0.014, MAE: 0.05) with linear efficiency (8.5k parameters, 0.18 ms inference) versus linear-only (MSE: 0.045) or large NN (200k parameters, 1.8 ms), supported by theoretical error bounds βˆ₯ 𝐸(π‘₯) βˆ₯≀βˆ₯𝑓(π‘₯) βˆ’ 𝐴π‘₯ βˆ₯ +πœ– and ablation studies confirming optimal interpretability-accuracy trade-offs. The linear-neural hybrid resolves fundamental modeling trade-offs, providing production-ready performance prediction with guaranteed error decomposition, staged training algorithms, and deployment strategies including sparsity constraints and online adaptation. KW - Performance Modeling KW - Linear Algebra KW - Neural Networks KW - Hybrid Models KW - Predictive Approximators KW - Digital Systems KW - Machine Learning KW - System Optimization DO -