sigmoidWi

SigmoidWi is a computational concept used in data processing and neural network design that refers to a sigmoid-weighted input transformation. In this approach, each input feature is modulated by a sigmoid gate, allowing nonlinear and bounded contributions to the subsequent computation. The idea is to apply a parametric sigmoid function to each input component before aggregation or further processing, effectively gating the influence of individual features.

Mathematically, for an input vector x = (x1, x2, ..., xn), each gated input is defined as gi = wi · sigma(ki · (xi − x0i)), where sigma(z) = 1 / (1 + exp(−z)) is the sigmoid function, wi is a feature-specific weight, ki controls the gate slope, and x0i sets the gate center. The resulting gated inputs can be combined in a variety of architectures, such as summing, concatenation, or feeding into subsequent layers.

Key properties include differentiability and boundedness: each gated contribution lies within a predictable range, and gradients can propagate through the gates during training. This can improve robustness to outliers and enable adaptive feature selection. However, the sigmoid gate introduces potential vanishing gradients when gates saturate, and excessive nonlinearity may complicate optimization if hyperparameters are not carefully tuned.

Applications of SigmoidWi span neural networks, time-series forecasting, sensor fusion, and gate-based architectures where selective, smooth control over input contributions is desirable. It is related to, but distinct from, traditional activation functions and attention mechanisms, offering a modular way to gate inputs at the feature level rather than globally.

See also: sigmoid function, gating mechanisms, feature scaling, attention, parametric activation functions.