VQ-based model for binary error process

Abstract

A variety of complex techniques, such as forward error correction (FEC), automatic repeat request (ARQ), hybrid ARQ or cross-layer optimization, require in their design and optimization phase a realistic model of binary error process present in a specific digital channel. Past and more recent modeling approaches focus on capturing one or more stochastic characteristics with precision sufficient for the desired model application, thereby applying concepts and methods severely limiting the model applicability (eg in the form of modeled process prerequisite expectations). The proposed novel concept utilizing a Vector Quantization (VQ)-based approach to binary process modeling offers a viable alternative capable of superior modeling of most commonly observed small-and large-scale stochastic characteristics of a binary error process on the digital channel. Precision of the proposed model was verified using multiple statistical distances against the data captured in a wireless sensor network logical channel trace. Furthermore, the Pearson's goodness of fit test of all model variants' output was performed to conclusively demonstrate usability of the model for realistic captured binary error process. Finally, the presented results prove the proposed model applicability and its ability to far surpass the capabilities of the reference Elliot's model. K e y w o r d s: binary error; VQ, wireless channel, logical channel, error model, wireless sensor network

Degradable piezoelectric biomaterials for wearable and implantable bioelectronics

“…On the contrary to low piezo-response from cellulose with amorphous components, a recordhigh shear piezoelectric constant d 25 was reported by Csoka et al in ultrathin aligned cellulose nanocrystals (CNC) thin films formed with the aids of shear force and electrical field. 85 The piezoelectric response from the CNC film was monitored by measuring the height deflection using a conductive AFM tip (Fig. 4c).…”