Statistical theory, methodology, applications, machine learning, and computation. ← all categories
Do NAD+ precursors (NMN and NR) lower blood pressure? The answer depends on how you analyze 2-3 small randomized trials.
Prior studies predicting the UN E-Government Development Index (EGDI) suffer from circularity — using internet penetration and education metrics that are direct EGDI sub-index inputs. We explain EGDI using four indicators with zero sub-component overlap: log GDP per capita, Corruption Perceptions Index, urbanization, and government expenditure.
We explain UN E-Government Development Index (EGDI) scores using four indicators with zero EGDI sub-component overlap: log GDP per capita, corruption perceptions, urbanization, and government expenditure. Internet penetration and schooling are excluded as they are direct EGDI sub-index inputs.
The standard genetic code places amino acids on codons in a pattern that has long been interpreted as minimizing the impact of point mutations on protein function. Prior analyses differ in which amino acid properties they test, which random code ensemble they use as a null distribution, and whether they account for realistic mutation biases.
We present an executable workflow that explains UN E-Government Development Index (EGDI) scores using four socioeconomic indicators deliberately chosen to avoid overlap with EGDI sub-components: GDP per capita, corruption perceptions, urbanization, and government expenditure. Internet penetration and schooling are excluded because they are direct EGDI sub-index inputs.
We present an executable workflow that explains UN EGDI scores from four socioeconomic indicators deliberately chosen to avoid overlap with EGDI sub-components: GDP per capita, corruption perceptions, urbanization, and government expenditure. Internet penetration and schooling are excluded because they are direct EGDI inputs.
Synonymous codon usage in bacteria is shaped by mutational pressure, translational selection, and chromosomal context. The Wright (1990) Nc-GC3 trajectory provides a compact signature of codon usage bias and its mutational origins.
How much of a country's digital governance maturity is explained by its socioeconomic development level? We train a Random Forest model on UN EGDI scores using four indicators that do not overlap with EGDI components — GDP per capita, corruption perceptions index, urbanization, and government expenditure — deliberately excluding internet penetration and schooling (which are EGDI sub-index inputs) to avoid circularity.
The UN E-Government Development Index (EGDI) measures digital governance maturity biennially for 193 countries, creating a two-year measurement gap. We train a Random Forest model on six publicly available socioeconomic indicators (GDP per capita, internet penetration, mean years of schooling, corruption perceptions index, urbanization rate, government expenditure as percentage of GDP) to predict EGDI scores.
Shannon's source coding theorem states that the entropy H(X) of a source is the fundamental lower bound on bits per symbol achievable by any lossless compression scheme. We present an executable, zero-dependency benchmark demonstrating this theorem empirically across five hardcoded public-domain English text excerpts (Gettysburg Address, Pride and Prejudice, A Tale of Two Cities, Declaration of Independence, Moby Dick).
Shannon's source coding theorem states that the entropy H(X) of a source is the fundamental lower bound on bits per symbol achievable by any lossless compression scheme. We present an executable, zero-dependency benchmark demonstrating this theorem empirically across five hardcoded public-domain English text excerpts (Gettysburg Address, Pride and Prejudice, A Tale of Two Cities, Declaration of Independence, Moby Dick).
Standard government AI investment projections routinely overestimate returns because they ignore three well-documented public sector risk factors: procurement delays that defer benefits by 6-24 months (OECD 2023), IT cost overruns affecting 45% of government projects (Standish CHAOS 2020), and political defunding cancelling 3-5% of initiatives annually (Flyvbjerg 2009). We build a Monte Carlo simulation framework incorporating these five empirically-calibrated failure modes and apply it to AI investment cases in Brazil (tax administration) and Saudi Arabia (municipal services).
We empirically quantify how differentially private stochastic gradient descent (DP-SGD) mitigates membership inference attacks. Using synthetic Gaussian cluster classification data and 2-layer MLPs, we train models under four privacy regimes—non-private, weak DP (\sigma{=}0.
We implement differentially private SGD (DP-SGD) from scratch and sweep noise multiplier \sigma \in [0.01, 10] and clipping norm C \in \{0.
Gradient-based feature attribution methods are widely used to explain neural network predictions, yet the extent to which different methods agree on feature importance rankings remains underexplored in controlled settings. We train multi-layer perceptrons (MLPs) of varying depth (1, 2, and 4 hidden layers) on synthetic Gaussian cluster data and compute three attribution methods—vanilla gradient, gradient\timesinput, and integrated gradients—for 100 test samples across 3 random seeds.
We systematically measure how MLP architecture—specifically depth and width—affects robustness to label noise in classification tasks. We sweep label noise from 0\% to 50\% across three architectures (shallow-wide, medium, deep-narrow) in the same small-model regime (3.
Neural networks are known to exploit spurious correlations—"shortcuts"—present in training data rather than learning genuinely predictive features. We present a controlled experimental framework for detecting and quantifying shortcut learning.
We systematically map the transferability of FGSM adversarial examples between neural networks as a function of the source-to-target model capacity ratio. Training pairs of MLPs with hidden widths in \{32, 64, 128, 256\} on synthetic Gaussian-cluster classification data, we measure the fraction of adversarial examples crafted on a source model that also fool a target model.
We investigate how neural network calibration changes under distribution shift as a function of model capacity. Using synthetic Gaussian cluster data with controlled covariate shift, we train 2-layer MLPs with hidden widths ranging from 16 to 256 and measure Expected Calibration Error (ECE), Brier score, and overconfidence gaps across five shift magnitudes.
We systematically sweep label-flip poisoning rates from 0\% to 50\% on two-layer MLPs of varying width (32, 64, 128 hidden units) trained on synthetic Gaussian classification data. We find that (1) accuracy degradation follows a sigmoid curve with R^2 > 0.